DTU ProjectLab - User contributions [en-gb]

Gantt Charts

2021-03-22T19:16:42Z

S175068:

A page describing Gantt Charts as a tool in Project Management, made as part of the course 42433 Advanced Engineering Project, Program and Portfolio Management F21 on DTU.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. Then it discusses the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts, to help the reader get started using the tool.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added features <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref> <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref> <ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>. During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>.

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>. Gantt Charts are also well integrated with the big ERP-systems like SAP, here the software can automatically check if e.g., resources are available at a given time according to the schedule and it can automatically generate the Gantt Charts to visualize the complete plan <ref> Kalaimani, Jayaraman. SAP Project Management Pitfalls: How to Avoid the Most Common Pitfalls of an SAP Solution. 1st ed., Apress, 2015, page 49-55 </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which software the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref>. Besides this, milestones are a great place to mark the completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency <ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, the dependencies are visualized in figure 5, according to the figure the following examples are given:
#Finish to start (FS), task 3 cannot start until task 2 is finished.
#Start to start (SS), task 4 cannot start until task 3 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.
#Start to finish (SF), task 6 cannot be finished until task 5 is started.

[[File:Gantt Chart microsoft project dependency true.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

Dependencies can also contain a lead or a lag time. In these examples, the lead and lag time is 2 days and they are added to the FS dependency. Lead and lag time can be added on any type of dependency and be any desired length.
#Lead time (- # days), task 7 cannot start until 2 days before task 6 is finished.
#Lag time (+ # days), task 8 cannot start until 2 days after task 7 finished.

Lead and lag time can be beneficial e.g., lag time might be used if a casted wall needs to be painted. The wall might need to dry for two days before the painting can be started thus there is a lag time of two days.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
[[File:Gantt Chart microsoft project progress.png|thumb|400px|Figure 6: Progress in Microsoft Project, own creation]]

The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

In figure 6 the progress can be seen as it is visualized in Microsoft Project. The progress is shown as the darker color in the middle of the bars. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>.

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning <ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support department. If these tasks are planned at the same time, the support deapartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the team members performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the team members the progress and the critical tasks that might be in the project <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the team members e.g., on a board meeting, and making sure it is always visual to keep the team members aware of deadlines, etc. It is important to update the chart, so it presents the actual state of the project.

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control <ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and confuse the user, thus be a disadvantage for the project manager. If the Gantt Chart gets too complex and a change happens in the project, there might be a risk that the project manager does not have the necessary time to update the Gantt Chart. This can end up in an outdated Gantt Chart <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref>. Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software <ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>.

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>.

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus in the article is, projects in the construction industry <ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-28T11:05:48Z

S175068: /* Annotated Bibliography */

A page describing Gantt Charts as a tool in Project Management by Bente Meidahl Münsberg s175068, as part of the course 42433 Advanced Engineering Project, Program and Portfolio Management F21 on DTU.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. Then it discusses the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts, to help the reader get started using the tool.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added features <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref> <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref> <ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>. During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>.

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>. Gantt Charts are also well integrated with the big ERP-systems like SAP, here the software can automatically check if e.g., resources are available at a given time according to the schedule and it can automatically generate the Gantt Charts to visualize the complete plan <ref> Kalaimani, Jayaraman. SAP Project Management Pitfalls: How to Avoid the Most Common Pitfalls of an SAP Solution. 1st ed., Apress, 2015, page 49-55 </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which software the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref>. Besides this, milestones are a great place to mark the completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency <ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, the dependencies are visualized in figure 5, according to the figure the following examples are given:
#Finish to start (FS), task 3 cannot start until task 2 is finished.
#Start to start (SS), task 4 cannot start until task 3 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.
#Start to finish (SF), task 6 cannot be finished until task 5 is started.

[[File:Gantt Chart microsoft project dependency true.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

Dependencies can also contain a lead or a lag time. In these examples, the lead and lag time is 2 days and they are added to the FS dependency. Lead and lag time can be added on any type of dependency and be any desired length.
#Lead time (- # days), task 7 cannot start until 2 days before task 6 is finished.
#Lag time (+ # days), task 8 cannot start until 2 days after task 7 finished.

Lead and lag time can be beneficial e.g., lag time might be used if a casted wall needs to be painted. The wall might need to dry for two days before the painting can be started thus there is a lag time of two days.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
[[File:Gantt Chart microsoft project progress.png|thumb|400px|Figure 6: Progress in Microsoft Project, own creation]]

The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

In figure 6 the progress can be seen as it is visualized in Microsoft Project. The progress is shown as the darker color in the middle of the bars. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>.

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning <ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support department. If these tasks are planned at the same time, the support deapartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the team members performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the team members the progress and the critical tasks that might be in the project <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the team members e.g., on a board meeting, and making sure it is always visual to keep the team members aware of deadlines, etc. It is important to update the chart, so it presents the actual state of the project.

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control <ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and confuse the user, thus be a disadvantage for the project manager. If the Gantt Chart gets too complex and a change happens in the project, there might be a risk that the project manager does not have the necessary time to update the Gantt Chart. This can end up in an outdated Gantt Chart <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref>. Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software <ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>.

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>.

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus in the article is, projects in the construction industry <ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-28T11:03:31Z

S175068: /* Level of detail */

A page describing Gantt Charts as a tool in Project Management by Bente Meidahl Münsberg s175068, as part of the course 42433 Advanced Engineering Project, Program and Portfolio Management F21 on DTU.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. Then it discusses the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts, to help the reader get started using the tool.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added features <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref> <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref> <ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>. During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>.

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>. Gantt Charts are also well integrated with the big ERP-systems like SAP, here the software can automatically check if e.g., resources are available at a given time according to the schedule and it can automatically generate the Gantt Charts to visualize the complete plan <ref> Kalaimani, Jayaraman. SAP Project Management Pitfalls: How to Avoid the Most Common Pitfalls of an SAP Solution. 1st ed., Apress, 2015, page 49-55 </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which software the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref>. Besides this, milestones are a great place to mark the completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency <ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, the dependencies are visualized in figure 5, according to the figure the following examples are given:
#Finish to start (FS), task 3 cannot start until task 2 is finished.
#Start to start (SS), task 4 cannot start until task 3 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.
#Start to finish (SF), task 6 cannot be finished until task 5 is started.

[[File:Gantt Chart microsoft project dependency true.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

Dependencies can also contain a lead or a lag time. In these examples, the lead and lag time is 2 days and they are added to the FS dependency. Lead and lag time can be added on any type of dependency and be any desired length.
#Lead time (- # days), task 7 cannot start until 2 days before task 6 is finished.
#Lag time (+ # days), task 8 cannot start until 2 days after task 7 finished.

Lead and lag time can be beneficial e.g., lag time might be used if a casted wall needs to be painted. The wall might need to dry for two days before the painting can be started thus there is a lag time of two days.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
[[File:Gantt Chart microsoft project progress.png|thumb|400px|Figure 6: Progress in Microsoft Project, own creation]]

The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

In figure 6 the progress can be seen as it is visualized in Microsoft Project. The progress is shown as the darker color in the middle of the bars. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>.

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning <ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support department. If these tasks are planned at the same time, the support deapartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the team members performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the team members the progress and the critical tasks that might be in the project <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the team members e.g., on a board meeting, and making sure it is always visual to keep the team members aware of deadlines, etc. It is important to update the chart, so it presents the actual state of the project.

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control <ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and confuse the user, thus be a disadvantage for the project manager. If the Gantt Chart gets too complex and a change happens in the project, there might be a risk that the project manager does not have the necessary time to update the Gantt Chart. This can end up in an outdated Gantt Chart <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref>. Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software <ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>.

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>.

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-28T11:03:11Z

S175068: /* Level of detail */

A page describing Gantt Charts as a tool in Project Management by Bente Meidahl Münsberg s175068, as part of the course 42433 Advanced Engineering Project, Program and Portfolio Management F21 on DTU.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. Then it discusses the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts, to help the reader get started using the tool.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added features <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref> <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref> <ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>. During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>.

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>. Gantt Charts are also well integrated with the big ERP-systems like SAP, here the software can automatically check if e.g., resources are available at a given time according to the schedule and it can automatically generate the Gantt Charts to visualize the complete plan <ref> Kalaimani, Jayaraman. SAP Project Management Pitfalls: How to Avoid the Most Common Pitfalls of an SAP Solution. 1st ed., Apress, 2015, page 49-55 </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which software the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref>. Besides this, milestones are a great place to mark the completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency <ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, the dependencies are visualized in figure 5, according to the figure the following examples are given:
#Finish to start (FS), task 3 cannot start until task 2 is finished.
#Start to start (SS), task 4 cannot start until task 3 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.
#Start to finish (SF), task 6 cannot be finished until task 5 is started.

[[File:Gantt Chart microsoft project dependency true.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

Dependencies can also contain a lead or a lag time. In these examples, the lead and lag time is 2 days and they are added to the FS dependency. Lead and lag time can be added on any type of dependency and be any desired length.
#Lead time (- # days), task 7 cannot start until 2 days before task 6 is finished.
#Lag time (+ # days), task 8 cannot start until 2 days after task 7 finished.

Lead and lag time can be beneficial e.g., lag time might be used if a casted wall needs to be painted. The wall might need to dry for two days before the painting can be started thus there is a lag time of two days.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
[[File:Gantt Chart microsoft project progress.png|thumb|400px|Figure 6: Progress in Microsoft Project, own creation]]

The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

In figure 6 the progress can be seen as it is visualized in Microsoft Project. The progress is shown as the darker color in the middle of the bars. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>.

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning <ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support department. If these tasks are planned at the same time, the support deapartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the team members performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the team members the progress and the critical tasks that might be in the project <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the team members e.g., on a board meeting, and making sure it is always visual to keep the team members aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control <ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and confuse the user, thus be a disadvantage for the project manager. If the Gantt Chart gets too complex and a change happens in the project, there might be a risk that the project manager does not have the necessary time to update the Gantt Chart. This can end up in an outdated Gantt Chart <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref>. Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software <ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>.

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>.

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-28T10:59:46Z

S175068: /* Responsibility and resources */

A page describing Gantt Charts as a tool in Project Management by Bente Meidahl Münsberg s175068, as part of the course 42433 Advanced Engineering Project, Program and Portfolio Management F21 on DTU.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. Then it discusses the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts, to help the reader get started using the tool.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added features <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref> <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref> <ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>. During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>.

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>. Gantt Charts are also well integrated with the big ERP-systems like SAP, here the software can automatically check if e.g., resources are available at a given time according to the schedule and it can automatically generate the Gantt Charts to visualize the complete plan <ref> Kalaimani, Jayaraman. SAP Project Management Pitfalls: How to Avoid the Most Common Pitfalls of an SAP Solution. 1st ed., Apress, 2015, page 49-55 </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which software the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref>. Besides this, milestones are a great place to mark the completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency <ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, the dependencies are visualized in figure 5, according to the figure the following examples are given:
#Finish to start (FS), task 3 cannot start until task 2 is finished.
#Start to start (SS), task 4 cannot start until task 3 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.
#Start to finish (SF), task 6 cannot be finished until task 5 is started.

[[File:Gantt Chart microsoft project dependency true.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

Dependencies can also contain a lead or a lag time. In these examples, the lead and lag time is 2 days and they are added to the FS dependency. Lead and lag time can be added on any type of dependency and be any desired length.
#Lead time (- # days), task 7 cannot start until 2 days before task 6 is finished.
#Lag time (+ # days), task 8 cannot start until 2 days after task 7 finished.

Lead and lag time can be beneficial e.g., lag time might be used if a casted wall needs to be painted. The wall might need to dry for two days before the painting can be started thus there is a lag time of two days.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
[[File:Gantt Chart microsoft project progress.png|thumb|400px|Figure 6: Progress in Microsoft Project, own creation]]

The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

In figure 6 the progress can be seen as it is visualized in Microsoft Project. The progress is shown as the darker color in the middle of the bars. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>.

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning <ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support department. If these tasks are planned at the same time, the support deapartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control <ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and confuse the user, thus be a disadvantage for the project manager. If the Gantt Chart gets too complex and a change happens in the project, there might be a risk that the project manager does not have the necessary time to update the Gantt Chart. This can end up in an outdated Gantt Chart <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref>. Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software <ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>.

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>.

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-28T10:59:24Z

S175068: /* Milestones */

A page describing Gantt Charts as a tool in Project Management by Bente Meidahl Münsberg s175068, as part of the course 42433 Advanced Engineering Project, Program and Portfolio Management F21 on DTU.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. Then it discusses the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts, to help the reader get started using the tool.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added features <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref> <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref> <ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>. During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>.

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>. Gantt Charts are also well integrated with the big ERP-systems like SAP, here the software can automatically check if e.g., resources are available at a given time according to the schedule and it can automatically generate the Gantt Charts to visualize the complete plan <ref> Kalaimani, Jayaraman. SAP Project Management Pitfalls: How to Avoid the Most Common Pitfalls of an SAP Solution. 1st ed., Apress, 2015, page 49-55 </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which software the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref>. Besides this, milestones are a great place to mark the completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency <ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, the dependencies are visualized in figure 5, according to the figure the following examples are given:
#Finish to start (FS), task 3 cannot start until task 2 is finished.
#Start to start (SS), task 4 cannot start until task 3 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.
#Start to finish (SF), task 6 cannot be finished until task 5 is started.

[[File:Gantt Chart microsoft project dependency true.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

Dependencies can also contain a lead or a lag time. In these examples, the lead and lag time is 2 days and they are added to the FS dependency. Lead and lag time can be added on any type of dependency and be any desired length.
#Lead time (- # days), task 7 cannot start until 2 days before task 6 is finished.
#Lag time (+ # days), task 8 cannot start until 2 days after task 7 finished.

Lead and lag time can be beneficial e.g., lag time might be used if a casted wall needs to be painted. The wall might need to dry for two days before the painting can be started thus there is a lag time of two days.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
[[File:Gantt Chart microsoft project progress.png|thumb|400px|Figure 6: Progress in Microsoft Project, own creation]]

The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

In figure 6 the progress can be seen as it is visualized in Microsoft Project. The progress is shown as the darker color in the middle of the bars. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>.

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning <ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support department. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control <ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and confuse the user, thus be a disadvantage for the project manager. If the Gantt Chart gets too complex and a change happens in the project, there might be a risk that the project manager does not have the necessary time to update the Gantt Chart. This can end up in an outdated Gantt Chart <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref>. Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software <ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>.

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>.

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-28T10:58:56Z

S175068: /* Features of the Gantt Chart */

A page describing Gantt Charts as a tool in Project Management by Bente Meidahl Münsberg s175068, as part of the course 42433 Advanced Engineering Project, Program and Portfolio Management F21 on DTU.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. Then it discusses the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts, to help the reader get started using the tool.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added features <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref> <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref> <ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>. During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>.

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>. Gantt Charts are also well integrated with the big ERP-systems like SAP, here the software can automatically check if e.g., resources are available at a given time according to the schedule and it can automatically generate the Gantt Charts to visualize the complete plan <ref> Kalaimani, Jayaraman. SAP Project Management Pitfalls: How to Avoid the Most Common Pitfalls of an SAP Solution. 1st ed., Apress, 2015, page 49-55 </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which software the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref>. Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency <ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, the dependencies are visualized in figure 5, according to the figure the following examples are given:
#Finish to start (FS), task 3 cannot start until task 2 is finished.
#Start to start (SS), task 4 cannot start until task 3 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.
#Start to finish (SF), task 6 cannot be finished until task 5 is started.

[[File:Gantt Chart microsoft project dependency true.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

Dependencies can also contain a lead or a lag time. In these examples, the lead and lag time is 2 days and they are added to the FS dependency. Lead and lag time can be added on any type of dependency and be any desired length.
#Lead time (- # days), task 7 cannot start until 2 days before task 6 is finished.
#Lag time (+ # days), task 8 cannot start until 2 days after task 7 finished.

Lead and lag time can be beneficial e.g., lag time might be used if a casted wall needs to be painted. The wall might need to dry for two days before the painting can be started thus there is a lag time of two days.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
[[File:Gantt Chart microsoft project progress.png|thumb|400px|Figure 6: Progress in Microsoft Project, own creation]]

The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

In figure 6 the progress can be seen as it is visualized in Microsoft Project. The progress is shown as the darker color in the middle of the bars. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>.

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning <ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support department. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control <ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and confuse the user, thus be a disadvantage for the project manager. If the Gantt Chart gets too complex and a change happens in the project, there might be a risk that the project manager does not have the necessary time to update the Gantt Chart. This can end up in an outdated Gantt Chart <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref>. Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software <ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>.

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>.

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-27T12:27:55Z

S175068: /* Progress */

A page describing Gantt Charts as a tool in Project Management by Bente Meidahl Münsberg s175068, as part of the course 42433 Advanced Engineering Project, Program and Portfolio Management F21 on DTU.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. Then it discusses the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts, to help the reader get started using the tool.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added features <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref> <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref> <ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>. During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>.

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>. Gantt Charts are also well integrated with the big ERP-systems like SAP, here the software can automatically check if e.g., resources are available at a given time according to the schedule and it can automatically generate the Gantt Charts to visualize the complete plan <ref> Kalaimani, Jayaraman. SAP Project Management Pitfalls: How to Avoid the Most Common Pitfalls of an SAP Solution. 1st ed., Apress, 2015, page 49-55 </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref>. Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency <ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, the dependencies are visualized in figure 5, according to the figure the following examples are given:
#Finish to start (FS), task 3 cannot start until task 2 is finished.
#Start to start (SS), task 4 cannot start until task 3 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.
#Start to finish (SF), task 6 cannot be finished until task 5 is started.

[[File:Gantt Chart microsoft project dependency true.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

Dependencies can also contain a lead or a lag time. In these examples, the lead and lag time is 2 days and they are added to the FS dependency. Lead and lag time can be added on any type of dependency and be any desired length.
#Lead time (- # days), task 7 cannot start until 2 days before task 6 is finished.
#Lag time (+ # days), task 8 cannot start until 2 days after task 7 finished.

Lead and lag time can be beneficial e.g., lag time might be used if a casted wall needs to be painted. The wall might need to dry for two days before the painting can be started thus there is a lag time of two days.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
[[File:Gantt Chart microsoft project progress.png|thumb|400px|Figure 6: Progress in Microsoft Project, own creation]]

The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

In figure 6 the progress can be seen as it is visualized in Microsoft Project. The progress is shown as the darker color in the middle of the bars. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>.

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning <ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support department. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control <ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and confuse the user, thus be a disadvantage for the project manager. If the Gantt Chart gets too complex and a change happens in the project, there might be a risk that the project manager does not have the necessary time to update the Gantt Chart. This can end up in an outdated Gantt Chart <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref>. Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software <ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>.

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>.

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-27T12:26:37Z

S175068:

A page describing Gantt Charts as a tool in Project Management by Bente Meidahl Münsberg s175068, as part of the course 42433 Advanced Engineering Project, Program and Portfolio Management F21 on DTU.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. Then it discusses the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts, to help the reader get started using the tool.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added features <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref> <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref> <ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>. During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>.

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>. Gantt Charts are also well integrated with the big ERP-systems like SAP, here the software can automatically check if e.g., resources are available at a given time according to the schedule and it can automatically generate the Gantt Charts to visualize the complete plan <ref> Kalaimani, Jayaraman. SAP Project Management Pitfalls: How to Avoid the Most Common Pitfalls of an SAP Solution. 1st ed., Apress, 2015, page 49-55 </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref>. Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency <ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, the dependencies are visualized in figure 5, according to the figure the following examples are given:
#Finish to start (FS), task 3 cannot start until task 2 is finished.
#Start to start (SS), task 4 cannot start until task 3 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.
#Start to finish (SF), task 6 cannot be finished until task 5 is started.

[[File:Gantt Chart microsoft project dependency true.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

Dependencies can also contain a lead or a lag time. In these examples, the lead and lag time is 2 days and they are added to the FS dependency. Lead and lag time can be added on any type of dependency and be any desired length.
#Lead time (- # days), task 7 cannot start until 2 days before task 6 is finished.
#Lag time (+ # days), task 8 cannot start until 2 days after task 7 finished.

Lead and lag time can be beneficial e.g., lag time might be used if a casted wall needs to be painted. The wall might need to dry for two days before the painting can be started thus there is a lag time of two days.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

[[File:Gantt Chart microsoft project progress.png|thumb|500px|Figure 6: Progress in Microsoft Project, own creation]]

In figure 6 the progress can be seen as it is visualized in Microsoft Project. The progress is shown as the darker color in the middle of the bars. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>.

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning <ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support department. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control <ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and confuse the user, thus be a disadvantage for the project manager. If the Gantt Chart gets too complex and a change happens in the project, there might be a risk that the project manager does not have the necessary time to update the Gantt Chart. This can end up in an outdated Gantt Chart <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref>. Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software <ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>.

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>.

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-27T12:24:13Z

S175068: /* Useful programs to produce Gantt Charts */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. Then it discusses the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts, to help the reader get started using the tool.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added features <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref> <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref> <ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>. During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>.

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>. Gantt Charts are also well integrated with the big ERP-systems like SAP, here the software can automatically check if e.g., resources are available at a given time according to the schedule and it can automatically generate the Gantt Charts to visualize the complete plan <ref> Kalaimani, Jayaraman. SAP Project Management Pitfalls: How to Avoid the Most Common Pitfalls of an SAP Solution. 1st ed., Apress, 2015, page 49-55 </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref>. Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency <ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, the dependencies are visualized in figure 5, according to the figure the following examples are given:
#Finish to start (FS), task 3 cannot start until task 2 is finished.
#Start to start (SS), task 4 cannot start until task 3 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.
#Start to finish (SF), task 6 cannot be finished until task 5 is started.

[[File:Gantt Chart microsoft project dependency true.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

Dependencies can also contain a lead or a lag time. In these examples, the lead and lag time is 2 days and they are added to the FS dependency. Lead and lag time can be added on any type of dependency and be any desired length.
#Lead time (- # days), task 7 cannot start until 2 days before task 6 is finished.
#Lag time (+ # days), task 8 cannot start until 2 days after task 7 finished.

Lead and lag time can be beneficial e.g., lag time might be used if a casted wall needs to be painted. The wall might need to dry for two days before the painting can be started thus there is a lag time of two days.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

[[File:Gantt Chart microsoft project progress.png|thumb|500px|Figure 6: Progress in Microsoft Project, own creation]]

In figure 6 the progress can be seen as it is visualized in Microsoft Project. The progress is shown as the darker color in the middle of the bars. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>.

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning <ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support department. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control <ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and confuse the user, thus be a disadvantage for the project manager. If the Gantt Chart gets too complex and a change happens in the project, there might be a risk that the project manager does not have the necessary time to update the Gantt Chart. This can end up in an outdated Gantt Chart <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref>. Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software <ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>.

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>.

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-27T12:23:27Z

S175068: /* Limitations of the Gantt Chart */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. Then it discusses the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts, to help the reader get started using the tool.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added features <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref> <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref> <ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>. During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>.

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>. Gantt Charts are also well integrated with the big ERP-systems like SAP, here the software can automatically check if e.g., resources are available at a given time according to the schedule and it can automatically generate the Gantt Charts to visualize the complete plan <ref> Kalaimani, Jayaraman. SAP Project Management Pitfalls: How to Avoid the Most Common Pitfalls of an SAP Solution. 1st ed., Apress, 2015, page 49-55 </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref>. Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency <ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, the dependencies are visualized in figure 5, according to the figure the following examples are given:
#Finish to start (FS), task 3 cannot start until task 2 is finished.
#Start to start (SS), task 4 cannot start until task 3 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.
#Start to finish (SF), task 6 cannot be finished until task 5 is started.

[[File:Gantt Chart microsoft project dependency true.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

Dependencies can also contain a lead or a lag time. In these examples, the lead and lag time is 2 days and they are added to the FS dependency. Lead and lag time can be added on any type of dependency and be any desired length.
#Lead time (- # days), task 7 cannot start until 2 days before task 6 is finished.
#Lag time (+ # days), task 8 cannot start until 2 days after task 7 finished.

Lead and lag time can be beneficial e.g., lag time might be used if a casted wall needs to be painted. The wall might need to dry for two days before the painting can be started thus there is a lag time of two days.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

[[File:Gantt Chart microsoft project progress.png|thumb|500px|Figure 6: Progress in Microsoft Project, own creation]]

In figure 6 the progress can be seen as it is visualized in Microsoft Project. The progress is shown as the darker color in the middle of the bars. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>.

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning <ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support department. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control <ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and confuse the user, thus be a disadvantage for the project manager. If the Gantt Chart gets too complex and a change happens in the project, there might be a risk that the project manager does not have the necessary time to update the Gantt Chart. This can end up in an outdated Gantt Chart <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref>. Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software <ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-27T12:22:54Z

S175068: /* Level of detail */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. Then it discusses the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts, to help the reader get started using the tool.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added features <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref> <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref> <ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>. During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>.

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>. Gantt Charts are also well integrated with the big ERP-systems like SAP, here the software can automatically check if e.g., resources are available at a given time according to the schedule and it can automatically generate the Gantt Charts to visualize the complete plan <ref> Kalaimani, Jayaraman. SAP Project Management Pitfalls: How to Avoid the Most Common Pitfalls of an SAP Solution. 1st ed., Apress, 2015, page 49-55 </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref>. Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency <ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, the dependencies are visualized in figure 5, according to the figure the following examples are given:
#Finish to start (FS), task 3 cannot start until task 2 is finished.
#Start to start (SS), task 4 cannot start until task 3 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.
#Start to finish (SF), task 6 cannot be finished until task 5 is started.

[[File:Gantt Chart microsoft project dependency true.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

Dependencies can also contain a lead or a lag time. In these examples, the lead and lag time is 2 days and they are added to the FS dependency. Lead and lag time can be added on any type of dependency and be any desired length.
#Lead time (- # days), task 7 cannot start until 2 days before task 6 is finished.
#Lag time (+ # days), task 8 cannot start until 2 days after task 7 finished.

Lead and lag time can be beneficial e.g., lag time might be used if a casted wall needs to be painted. The wall might need to dry for two days before the painting can be started thus there is a lag time of two days.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

[[File:Gantt Chart microsoft project progress.png|thumb|500px|Figure 6: Progress in Microsoft Project, own creation]]

In figure 6 the progress can be seen as it is visualized in Microsoft Project. The progress is shown as the darker color in the middle of the bars. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>.

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning <ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support department. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and confuse the user, thus be a disadvantage for the project manager. If the Gantt Chart gets too complex and a change happens in the project, there might be a risk that the project manager does not have the necessary time to update the Gantt Chart. This can end up in an outdated Gantt Chart <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software <ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-27T12:22:36Z

S175068: /* Responsibility and resources */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. Then it discusses the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts, to help the reader get started using the tool.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added features <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref> <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref> <ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>. During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>.

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>. Gantt Charts are also well integrated with the big ERP-systems like SAP, here the software can automatically check if e.g., resources are available at a given time according to the schedule and it can automatically generate the Gantt Charts to visualize the complete plan <ref> Kalaimani, Jayaraman. SAP Project Management Pitfalls: How to Avoid the Most Common Pitfalls of an SAP Solution. 1st ed., Apress, 2015, page 49-55 </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref>. Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency <ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, the dependencies are visualized in figure 5, according to the figure the following examples are given:
#Finish to start (FS), task 3 cannot start until task 2 is finished.
#Start to start (SS), task 4 cannot start until task 3 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.
#Start to finish (SF), task 6 cannot be finished until task 5 is started.

[[File:Gantt Chart microsoft project dependency true.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

Dependencies can also contain a lead or a lag time. In these examples, the lead and lag time is 2 days and they are added to the FS dependency. Lead and lag time can be added on any type of dependency and be any desired length.
#Lead time (- # days), task 7 cannot start until 2 days before task 6 is finished.
#Lag time (+ # days), task 8 cannot start until 2 days after task 7 finished.

Lead and lag time can be beneficial e.g., lag time might be used if a casted wall needs to be painted. The wall might need to dry for two days before the painting can be started thus there is a lag time of two days.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

[[File:Gantt Chart microsoft project progress.png|thumb|500px|Figure 6: Progress in Microsoft Project, own creation]]

In figure 6 the progress can be seen as it is visualized in Microsoft Project. The progress is shown as the darker color in the middle of the bars. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>.

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning <ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support department. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and confuse the user, thus be a disadvantage for the project manager. If the Gantt Chart gets too complex and a change happens in the project, there might be a risk that the project manager does not have the necessary time to update the Gantt Chart. This can end up in an outdated Gantt Chart <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software <ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-27T12:22:14Z

S175068: /* Progress */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. Then it discusses the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts, to help the reader get started using the tool.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added features <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref> <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref> <ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>. During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>.

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>. Gantt Charts are also well integrated with the big ERP-systems like SAP, here the software can automatically check if e.g., resources are available at a given time according to the schedule and it can automatically generate the Gantt Charts to visualize the complete plan <ref> Kalaimani, Jayaraman. SAP Project Management Pitfalls: How to Avoid the Most Common Pitfalls of an SAP Solution. 1st ed., Apress, 2015, page 49-55 </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref>. Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency <ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, the dependencies are visualized in figure 5, according to the figure the following examples are given:
#Finish to start (FS), task 3 cannot start until task 2 is finished.
#Start to start (SS), task 4 cannot start until task 3 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.
#Start to finish (SF), task 6 cannot be finished until task 5 is started.

[[File:Gantt Chart microsoft project dependency true.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

Dependencies can also contain a lead or a lag time. In these examples, the lead and lag time is 2 days and they are added to the FS dependency. Lead and lag time can be added on any type of dependency and be any desired length.
#Lead time (- # days), task 7 cannot start until 2 days before task 6 is finished.
#Lag time (+ # days), task 8 cannot start until 2 days after task 7 finished.

Lead and lag time can be beneficial e.g., lag time might be used if a casted wall needs to be painted. The wall might need to dry for two days before the painting can be started thus there is a lag time of two days.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

[[File:Gantt Chart microsoft project progress.png|thumb|500px|Figure 6: Progress in Microsoft Project, own creation]]

In figure 6 the progress can be seen as it is visualized in Microsoft Project. The progress is shown as the darker color in the middle of the bars. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>.

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support deapartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and confuse the user, thus be a disadvantage for the project manager. If the Gantt Chart gets too complex and a change happens in the project, there might be a risk that the project manager does not have the necessary time to update the Gantt Chart. This can end up in an outdated Gantt Chart <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software <ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-27T12:21:43Z

S175068: /* Dependency */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. Then it discusses the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts, to help the reader get started using the tool.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added features <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref> <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref> <ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>. During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>.

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>. Gantt Charts are also well integrated with the big ERP-systems like SAP, here the software can automatically check if e.g., resources are available at a given time according to the schedule and it can automatically generate the Gantt Charts to visualize the complete plan <ref> Kalaimani, Jayaraman. SAP Project Management Pitfalls: How to Avoid the Most Common Pitfalls of an SAP Solution. 1st ed., Apress, 2015, page 49-55 </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref>. Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency <ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, the dependencies are visualized in figure 5, according to the figure the following examples are given:
#Finish to start (FS), task 3 cannot start until task 2 is finished.
#Start to start (SS), task 4 cannot start until task 3 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.
#Start to finish (SF), task 6 cannot be finished until task 5 is started.

[[File:Gantt Chart microsoft project dependency true.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

Dependencies can also contain a lead or a lag time. In these examples, the lead and lag time is 2 days and they are added to the FS dependency. Lead and lag time can be added on any type of dependency and be any desired length.
#Lead time (- # days), task 7 cannot start until 2 days before task 6 is finished.
#Lag time (+ # days), task 8 cannot start until 2 days after task 7 finished.

Lead and lag time can be beneficial e.g., lag time might be used if a casted wall needs to be painted. The wall might need to dry for two days before the painting can be started thus there is a lag time of two days.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

[[File:Gantt Chart microsoft project progress.png|thumb|500px|Figure 6: Progress in Microsoft Project, own creation]]

In figure 6 the progress can be seen as it is visualized in Microsoft Project. The progress is shown as the darker color in the middle of the bars. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget. <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support deapartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and confuse the user, thus be a disadvantage for the project manager. If the Gantt Chart gets too complex and a change happens in the project, there might be a risk that the project manager does not have the necessary time to update the Gantt Chart. This can end up in an outdated Gantt Chart <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software <ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-27T12:21:22Z

S175068: /* Milestones */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. Then it discusses the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts, to help the reader get started using the tool.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added features <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref> <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref> <ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>. During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>.

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>. Gantt Charts are also well integrated with the big ERP-systems like SAP, here the software can automatically check if e.g., resources are available at a given time according to the schedule and it can automatically generate the Gantt Charts to visualize the complete plan <ref> Kalaimani, Jayaraman. SAP Project Management Pitfalls: How to Avoid the Most Common Pitfalls of an SAP Solution. 1st ed., Apress, 2015, page 49-55 </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref>. Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, the dependencies are visualized in figure 5, according to the figure the following examples are given:
#Finish to start (FS), task 3 cannot start until task 2 is finished.
#Start to start (SS), task 4 cannot start until task 3 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.
#Start to finish (SF), task 6 cannot be finished until task 5 is started.

[[File:Gantt Chart microsoft project dependency true.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

Dependencies can also contain a lead or a lag time. In these examples, the lead and lag time is 2 days and they are added to the FS dependency. Lead and lag time can be added on any type of dependency and be any desired length.
#Lead time (- # days), task 7 cannot start until 2 days before task 6 is finished.
#Lag time (+ # days), task 8 cannot start until 2 days after task 7 finished.

Lead and lag time can be beneficial e.g., lag time might be used if a casted wall needs to be painted. The wall might need to dry for two days before the painting can be started thus there is a lag time of two days.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

[[File:Gantt Chart microsoft project progress.png|thumb|500px|Figure 6: Progress in Microsoft Project, own creation]]

In figure 6 the progress can be seen as it is visualized in Microsoft Project. The progress is shown as the darker color in the middle of the bars. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget. <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support deapartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and confuse the user, thus be a disadvantage for the project manager. If the Gantt Chart gets too complex and a change happens in the project, there might be a risk that the project manager does not have the necessary time to update the Gantt Chart. This can end up in an outdated Gantt Chart <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software <ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-27T12:20:31Z

S175068: /* Gantt Chart in Project Management */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. Then it discusses the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts, to help the reader get started using the tool.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added features <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref> <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref> <ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>. During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>.

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>. Gantt Charts are also well integrated with the big ERP-systems like SAP, here the software can automatically check if e.g., resources are available at a given time according to the schedule and it can automatically generate the Gantt Charts to visualize the complete plan <ref> Kalaimani, Jayaraman. SAP Project Management Pitfalls: How to Avoid the Most Common Pitfalls of an SAP Solution. 1st ed., Apress, 2015, page 49-55 </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref> Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, the dependencies are visualized in figure 5, according to the figure the following examples are given:
#Finish to start (FS), task 3 cannot start until task 2 is finished.
#Start to start (SS), task 4 cannot start until task 3 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.
#Start to finish (SF), task 6 cannot be finished until task 5 is started.

[[File:Gantt Chart microsoft project dependency true.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

Dependencies can also contain a lead or a lag time. In these examples, the lead and lag time is 2 days and they are added to the FS dependency. Lead and lag time can be added on any type of dependency and be any desired length.
#Lead time (- # days), task 7 cannot start until 2 days before task 6 is finished.
#Lag time (+ # days), task 8 cannot start until 2 days after task 7 finished.

Lead and lag time can be beneficial e.g., lag time might be used if a casted wall needs to be painted. The wall might need to dry for two days before the painting can be started thus there is a lag time of two days.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

[[File:Gantt Chart microsoft project progress.png|thumb|500px|Figure 6: Progress in Microsoft Project, own creation]]

In figure 6 the progress can be seen as it is visualized in Microsoft Project. The progress is shown as the darker color in the middle of the bars. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget. <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support deapartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and confuse the user, thus be a disadvantage for the project manager. If the Gantt Chart gets too complex and a change happens in the project, there might be a risk that the project manager does not have the necessary time to update the Gantt Chart. This can end up in an outdated Gantt Chart <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software <ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-27T12:19:22Z

S175068: /* Limitations of the Gantt Chart */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. Then it discusses the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts, to help the reader get started using the tool.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added fetures<ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref><ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref><ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>. During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>.

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>. Gantt Charts are also well integrated with the big ERP-systems like SAP, here the software can automatically check if e.g., resources are available at a given time according to the schedule and it can automatically generate the Gantt Charts to visualize the complete plan <ref> Kalaimani, Jayaraman. SAP Project Management Pitfalls: How to Avoid the Most Common Pitfalls of an SAP Solution. 1st ed., Apress, 2015, page 49-55 </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref> Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, the dependencies are visualized in figure 5, according to the figure the following examples are given:
#Finish to start (FS), task 3 cannot start until task 2 is finished.
#Start to start (SS), task 4 cannot start until task 3 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.
#Start to finish (SF), task 6 cannot be finished until task 5 is started.

[[File:Gantt Chart microsoft project dependency true.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

Dependencies can also contain a lead or a lag time. In these examples, the lead and lag time is 2 days and they are added to the FS dependency. Lead and lag time can be added on any type of dependency and be any desired length.
#Lead time (- # days), task 7 cannot start until 2 days before task 6 is finished.
#Lag time (+ # days), task 8 cannot start until 2 days after task 7 finished.

Lead and lag time can be beneficial e.g., lag time might be used if a casted wall needs to be painted. The wall might need to dry for two days before the painting can be started thus there is a lag time of two days.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

[[File:Gantt Chart microsoft project progress.png|thumb|500px|Figure 6: Progress in Microsoft Project, own creation]]

In figure 6 the progress can be seen as it is visualized in Microsoft Project. The progress is shown as the darker color in the middle of the bars. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget. <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support deapartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and confuse the user, thus be a disadvantage for the project manager. If the Gantt Chart gets too complex and a change happens in the project, there might be a risk that the project manager does not have the necessary time to update the Gantt Chart. This can end up in an outdated Gantt Chart <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software <ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-27T12:08:48Z

S175068: /* Dependency */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. Then it discusses the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts, to help the reader get started using the tool.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added fetures<ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref><ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref><ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>. During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>.

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>. Gantt Charts are also well integrated with the big ERP-systems like SAP, here the software can automatically check if e.g., resources are available at a given time according to the schedule and it can automatically generate the Gantt Charts to visualize the complete plan <ref> Kalaimani, Jayaraman. SAP Project Management Pitfalls: How to Avoid the Most Common Pitfalls of an SAP Solution. 1st ed., Apress, 2015, page 49-55 </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref> Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, the dependencies are visualized in figure 5, according to the figure the following examples are given:
#Finish to start (FS), task 3 cannot start until task 2 is finished.
#Start to start (SS), task 4 cannot start until task 3 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.
#Start to finish (SF), task 6 cannot be finished until task 5 is started.

[[File:Gantt Chart microsoft project dependency true.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

Dependencies can also contain a lead or a lag time. In these examples, the lead and lag time is 2 days and they are added to the FS dependency. Lead and lag time can be added on any type of dependency and be any desired length.
#Lead time (- # days), task 7 cannot start until 2 days before task 6 is finished.
#Lag time (+ # days), task 8 cannot start until 2 days after task 7 finished.

Lead and lag time can be beneficial e.g., lag time might be used if a casted wall needs to be painted. The wall might need to dry for two days before the painting can be started thus there is a lag time of two days.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

[[File:Gantt Chart microsoft project progress.png|thumb|500px|Figure 6: Progress in Microsoft Project, own creation]]

In figure 6 the progress can be seen as it is visualized in Microsoft Project. The progress is shown as the darker color in the middle of the bars. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget. <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support deapartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and confuse the user, thus be a disadvantage for the project manager. If the Gantt Chart gets too complex and a change happens, there is a risk of the

there is a risk of the Gantt Chart getting overly complicated, if all minor tasks are added when they arise, it can confuse the users and be a disadvantage for the project manager.
If the chart is unnecessarily complicated and a change happens in the project, there is a risk of the chart eventually ending outdated if the manager does not have the necessary time e.g., if they are busy managing the occurred problems. <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software<ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-27T12:07:58Z

S175068: /* Dependency */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. Then it discusses the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts, to help the reader get started using the tool.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added fetures<ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref><ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref><ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>. During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>.

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>. Gantt Charts are also well integrated with the big ERP-systems like SAP, here the software can automatically check if e.g., resources are available at a given time according to the schedule and it can automatically generate the Gantt Charts to visualize the complete plan <ref> Kalaimani, Jayaraman. SAP Project Management Pitfalls: How to Avoid the Most Common Pitfalls of an SAP Solution. 1st ed., Apress, 2015, page 49-55 </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref> Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, the dependencies are visualized in figure 5, according to the figure the following examples are given:
#Finish to start (FS#), task 3 cannot start until task 2 is finished.
#Start to start (SS#), task 4 cannot start until task 3 is started.
#Finish to finish (FF#), task 5 cannot be finished until task 4 is finished.
#Start to finish (SF#), task 6 cannot be finished until task 5 is started.

[[File:Gantt Chart microsoft project dependency true.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

Dependencies can also contain a lead or a lag time. In these examples, the lead and lag time is 2 days and they are added to the FS dependency. Lead and lag time can be added on any type of dependency and be any desired length.
#Lead time (XX - # days), task 7 cannot start until 2 days before task 6 is finished.
#Lag time (XX + # days), task 8 cannot start until 2 days after task 7 finished.

Lead and lag time can be beneficial e.g., lag time might be used if a casted wall needs to be painted. The wall might need to dry for two days before the painting can be started thus there is a lag time of two days.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

[[File:Gantt Chart microsoft project progress.png|thumb|500px|Figure 6: Progress in Microsoft Project, own creation]]

In figure 6 the progress can be seen as it is visualized in Microsoft Project. The progress is shown as the darker color in the middle of the bars. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget. <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support deapartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and confuse the user, thus be a disadvantage for the project manager. If the Gantt Chart gets too complex and a change happens, there is a risk of the

there is a risk of the Gantt Chart getting overly complicated, if all minor tasks are added when they arise, it can confuse the users and be a disadvantage for the project manager.
If the chart is unnecessarily complicated and a change happens in the project, there is a risk of the chart eventually ending outdated if the manager does not have the necessary time e.g., if they are busy managing the occurred problems. <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software<ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-27T11:51:40Z

S175068: /* Dependency */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. Then it discusses the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts, to help the reader get started using the tool.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added fetures<ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref><ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref><ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>. During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>.

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>. Gantt Charts are also well integrated with the big ERP-systems like SAP, here the software can automatically check if e.g., resources are available at a given time according to the schedule and it can automatically generate the Gantt Charts to visualize the complete plan <ref> Kalaimani, Jayaraman. SAP Project Management Pitfalls: How to Avoid the Most Common Pitfalls of an SAP Solution. 1st ed., Apress, 2015, page 49-55 </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref> Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, if task 5 are dependent on task 4:
#Finish to start (FS), task 5 cannot start until task 4 is finished.
#Start to start (SS), task 5 cannot start until task 4 is started.
#Start to finish (SF), task 5 cannot be finished until task 4 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.

A variation of these is that there can be added a lead time or lag time one these dependencies. This will normally be done by e.g., FS+2days, this means that task 5 cannot start until 2 days later than task 4 is finished. An example is a wall that was cast and needs to dry for two days before it can be painted. The task ‘painting’ will have a lag time of 2 days on the finish to start dependency on ‘casting’. Dependency visualized in Microsoft project can be seen in figure 5.

[[File:Gantt Chart microsoft project dependency true.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

[[File:Gantt Chart microsoft project progress.png|thumb|500px|Figure 6: Progress in Microsoft Project, own creation]]

In figure 6 the progress can be seen as it is visualized in Microsoft Project. The progress is shown as the darker color in the middle of the bars. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget. <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support deapartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and confuse the user, thus be a disadvantage for the project manager. If the Gantt Chart gets too complex and a change happens, there is a risk of the

there is a risk of the Gantt Chart getting overly complicated, if all minor tasks are added when they arise, it can confuse the users and be a disadvantage for the project manager.
If the chart is unnecessarily complicated and a change happens in the project, there is a risk of the chart eventually ending outdated if the manager does not have the necessary time e.g., if they are busy managing the occurred problems. <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software<ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

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A page describing Gantt Charts as a tool in Project Management.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. Then it discusses the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts, to help the reader get started using the tool.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added fetures<ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref><ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref><ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>. During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>.

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>. Gantt Charts are also well integrated with the big ERP-systems like SAP, here the software can automatically check if e.g., resources are available at a given time according to the schedule and it can automatically generate the Gantt Charts to visualize the complete plan <ref> Kalaimani, Jayaraman. SAP Project Management Pitfalls: How to Avoid the Most Common Pitfalls of an SAP Solution. 1st ed., Apress, 2015, page 49-55 </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref> Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, if task 5 are dependent on task 4:
#Finish to start (FS), task 5 cannot start until task 4 is finished.
#Start to start (SS), task 5 cannot start until task 4 is started.
#Start to finish (SF), task 5 cannot be finished until task 4 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.

A variation of these is that there can be added a lead time or lag time one these dependencies. This will normally be done by e.g., FS+2days, this means that task 5 cannot start until 2 days later than task 4 is finished. An example is a wall that was cast and needs to dry for two days before it can be painted. The task ‘painting’ will have a lag time of 2 days on the finish to start dependency on ‘casting’. Dependency visualized in Microsoft project can be seen in figure 5.

[[File:Gantt Chart microsoft project dependency.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

[[File:Gantt Chart microsoft project progress.png|thumb|500px|Figure 6: Progress in Microsoft Project, own creation]]

In figure 6 the progress can be seen as it is visualized in Microsoft Project. The progress is shown as the darker color in the middle of the bars. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget. <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support deapartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and confuse the user, thus be a disadvantage for the project manager. If the Gantt Chart gets too complex and a change happens, there is a risk of the

there is a risk of the Gantt Chart getting overly complicated, if all minor tasks are added when they arise, it can confuse the users and be a disadvantage for the project manager.
If the chart is unnecessarily complicated and a change happens in the project, there is a risk of the chart eventually ending outdated if the manager does not have the necessary time e.g., if they are busy managing the occurred problems. <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software<ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-27T11:13:49Z

S175068: /* Progress */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. Then it discusses the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts, to help the reader get started using the tool.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added fetures<ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref><ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref><ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>. During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>.

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>. Gantt Charts are also well integrated with the big ERP-systems like SAP, here the software can automatically check if e.g., resources are available at a given time according to the schedule and it can automatically generate the Gantt Charts to visualize the complete plan <ref> Kalaimani, Jayaraman. SAP Project Management Pitfalls: How to Avoid the Most Common Pitfalls of an SAP Solution. 1st ed., Apress, 2015, page 49-55 </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref> Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, if task 5 are dependent on task 4:
#Finish to start (FS), task 5 cannot start until task 4 is finished.
#Start to start (SS), task 5 cannot start until task 4 is started.
#Start to finish (SF), task 5 cannot be finished until task 4 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.

A variation of these is that there can be added a lead time or lag time one these dependencies. This will normally be done by e.g., FS+2days, this means that task 5 cannot start until 2 days later than task 4 is finished. An example is a wall that was cast and needs to dry for two days before it can be painted. The task ‘painting’ will have a lag time of 2 days on the finish to start dependency on ‘casting’. Dependency visualized in Microsoft project can be seen in figure 5.

[[File:Gantt Chart microsoft project dependency.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

[[File:Gantt Chart microsoft project progress.png|thumb|500px|Figure 6: Progress in Microsoft Project, own creation]]

In figure 6 the progress can be seen as it is visualized in Microsoft Project. The progress is shown as the darker color in the middle of the bars. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget. <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support deapartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and be a disadvantage for the project manager.

there is a risk of the Gantt Chart getting overly complicated, if all minor tasks are added when they arise, it can confuse the users and be a disadvantage for the project manager. If the chart is unnecessarily complicated and a change happens in the project, there is a risk of the chart eventually ending outdated if the manager does not have the necessary time e.g., if they are busy managing the occurred problems. <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software<ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-27T11:13:33Z

S175068: /* Abstract */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. Then it discusses the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts, to help the reader get started using the tool.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added fetures<ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref><ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref><ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>. During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>.

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>. Gantt Charts are also well integrated with the big ERP-systems like SAP, here the software can automatically check if e.g., resources are available at a given time according to the schedule and it can automatically generate the Gantt Charts to visualize the complete plan <ref> Kalaimani, Jayaraman. SAP Project Management Pitfalls: How to Avoid the Most Common Pitfalls of an SAP Solution. 1st ed., Apress, 2015, page 49-55 </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref> Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, if task 5 are dependent on task 4:
#Finish to start (FS), task 5 cannot start until task 4 is finished.
#Start to start (SS), task 5 cannot start until task 4 is started.
#Start to finish (SF), task 5 cannot be finished until task 4 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.

A variation of these is that there can be added a lead time or lag time one these dependencies. This will normally be done by e.g., FS+2days, this means that task 5 cannot start until 2 days later than task 4 is finished. An example is a wall that was cast and needs to dry for two days before it can be painted. The task ‘painting’ will have a lag time of 2 days on the finish to start dependency on ‘casting’. Dependency visualized in Microsoft project can be seen in figure 5.

[[File:Gantt Chart microsoft project dependency.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

[[File:Gantt Chart microsoft project progress.png|thumb|centre|500px|Figure 6: Progress in Microsoft Project, own creation]]

In figure 6 the progress can be seen as it is visualized in Microsoft Project. The progress is shown as the darker color in the middle of the bars. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget. <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support deapartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and be a disadvantage for the project manager.

there is a risk of the Gantt Chart getting overly complicated, if all minor tasks are added when they arise, it can confuse the users and be a disadvantage for the project manager. If the chart is unnecessarily complicated and a change happens in the project, there is a risk of the chart eventually ending outdated if the manager does not have the necessary time e.g., if they are busy managing the occurred problems. <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software<ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-27T11:11:22Z

S175068: /* Guideline on how to get started using Gantt Charts */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. It also gives a guideline on how to get started using Gantt Charts as well as discussing the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added fetures<ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref><ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref><ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>. During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>.

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>. Gantt Charts are also well integrated with the big ERP-systems like SAP, here the software can automatically check if e.g., resources are available at a given time according to the schedule and it can automatically generate the Gantt Charts to visualize the complete plan <ref> Kalaimani, Jayaraman. SAP Project Management Pitfalls: How to Avoid the Most Common Pitfalls of an SAP Solution. 1st ed., Apress, 2015, page 49-55 </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref> Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, if task 5 are dependent on task 4:
#Finish to start (FS), task 5 cannot start until task 4 is finished.
#Start to start (SS), task 5 cannot start until task 4 is started.
#Start to finish (SF), task 5 cannot be finished until task 4 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.

A variation of these is that there can be added a lead time or lag time one these dependencies. This will normally be done by e.g., FS+2days, this means that task 5 cannot start until 2 days later than task 4 is finished. An example is a wall that was cast and needs to dry for two days before it can be painted. The task ‘painting’ will have a lag time of 2 days on the finish to start dependency on ‘casting’. Dependency visualized in Microsoft project can be seen in figure 5.

[[File:Gantt Chart microsoft project dependency.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

[[File:Gantt Chart microsoft project progress.png|thumb|centre|500px|Figure 6: Progress in Microsoft Project, own creation]]

In figure 6 the progress can be seen as it is visualized in Microsoft Project. The progress is shown as the darker color in the middle of the bars. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget. <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support deapartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and be a disadvantage for the project manager.

there is a risk of the Gantt Chart getting overly complicated, if all minor tasks are added when they arise, it can confuse the users and be a disadvantage for the project manager. If the chart is unnecessarily complicated and a change happens in the project, there is a risk of the chart eventually ending outdated if the manager does not have the necessary time e.g., if they are busy managing the occurred problems. <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software<ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-27T11:10:53Z

S175068: /* Progress */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. It also gives a guideline on how to get started using Gantt Charts as well as discussing the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added fetures<ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref><ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref><ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>. During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>.

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>. Gantt Charts are also well integrated with the big ERP-systems like SAP, here the software can automatically check if e.g., resources are available at a given time according to the schedule and it can automatically generate the Gantt Charts to visualize the complete plan <ref> Kalaimani, Jayaraman. SAP Project Management Pitfalls: How to Avoid the Most Common Pitfalls of an SAP Solution. 1st ed., Apress, 2015, page 49-55 </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref> Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, if task 5 are dependent on task 4:
#Finish to start (FS), task 5 cannot start until task 4 is finished.
#Start to start (SS), task 5 cannot start until task 4 is started.
#Start to finish (SF), task 5 cannot be finished until task 4 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.

A variation of these is that there can be added a lead time or lag time one these dependencies. This will normally be done by e.g., FS+2days, this means that task 5 cannot start until 2 days later than task 4 is finished. An example is a wall that was cast and needs to dry for two days before it can be painted. The task ‘painting’ will have a lag time of 2 days on the finish to start dependency on ‘casting’. Dependency visualized in Microsoft project can be seen in figure 5.

[[File:Gantt Chart microsoft project dependency.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

[[File:Gantt Chart microsoft project progress.png|thumb|centre|500px|Figure 6: Progress in Microsoft Project, own creation]]

In figure 6 the progress can be seen as it is visualized in Microsoft Project. The progress is shown as the darker color in the middle of the bars. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget. <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support deapartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Guideline on how to get started using Gantt Charts =
'''Step 1:''' Decide on the level of detail.

'''Step 2:''' Decide on which tasks to include.

'''Step 3:''' Write the tasks in descending order in the column leftmost, from starting first to last.

'''Step 4:''' Select a start date.

'''Step 5:''' Ad duration for your tasks

'''Step 6:''' Add predecessors.

'''Step 7:''' Depending on the automation of your software, maybe start and finish for all some or all tasks are filled out, if not fill out the remaining.

'''Step 8:''' Add additional features you need like responsibility, resources, critical path, milestones, progress etc.

'''Step 9:''' Update the Gantt Chart during the execution of the project

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and be a disadvantage for the project manager.

there is a risk of the Gantt Chart getting overly complicated, if all minor tasks are added when they arise, it can confuse the users and be a disadvantage for the project manager. If the chart is unnecessarily complicated and a change happens in the project, there is a risk of the chart eventually ending outdated if the manager does not have the necessary time e.g., if they are busy managing the occurred problems. <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software<ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-27T11:07:08Z

S175068: /* Historical State of the Art */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. It also gives a guideline on how to get started using Gantt Charts as well as discussing the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added fetures<ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref><ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref><ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>. During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>.

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>. Gantt Charts are also well integrated with the big ERP-systems like SAP, here the software can automatically check if e.g., resources are available at a given time according to the schedule and it can automatically generate the Gantt Charts to visualize the complete plan <ref> Kalaimani, Jayaraman. SAP Project Management Pitfalls: How to Avoid the Most Common Pitfalls of an SAP Solution. 1st ed., Apress, 2015, page 49-55 </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref> Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, if task 5 are dependent on task 4:
#Finish to start (FS), task 5 cannot start until task 4 is finished.
#Start to start (SS), task 5 cannot start until task 4 is started.
#Start to finish (SF), task 5 cannot be finished until task 4 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.

A variation of these is that there can be added a lead time or lag time one these dependencies. This will normally be done by e.g., FS+2days, this means that task 5 cannot start until 2 days later than task 4 is finished. An example is a wall that was cast and needs to dry for two days before it can be painted. The task ‘painting’ will have a lag time of 2 days on the finish to start dependency on ‘casting’. Dependency visualized in Microsoft project can be seen in figure 5.

[[File:Gantt Chart microsoft project dependency.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

[[File:Gantt Chart microsoft project progress.png|thumb|centre|500px|Figure 6: Progress in Microsoft Project, own creation]]

In figure 6 the progress can be seen as it is visualized in Microsoft Project, the middle of the bars change color. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget. <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support deapartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Guideline on how to get started using Gantt Charts =
'''Step 1:''' Decide on the level of detail.

'''Step 2:''' Decide on which tasks to include.

'''Step 3:''' Write the tasks in descending order in the column leftmost, from starting first to last.

'''Step 4:''' Select a start date.

'''Step 5:''' Ad duration for your tasks

'''Step 6:''' Add predecessors.

'''Step 7:''' Depending on the automation of your software, maybe start and finish for all some or all tasks are filled out, if not fill out the remaining.

'''Step 8:''' Add additional features you need like responsibility, resources, critical path, milestones, progress etc.

'''Step 9:''' Update the Gantt Chart during the execution of the project

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and be a disadvantage for the project manager.

there is a risk of the Gantt Chart getting overly complicated, if all minor tasks are added when they arise, it can confuse the users and be a disadvantage for the project manager. If the chart is unnecessarily complicated and a change happens in the project, there is a risk of the chart eventually ending outdated if the manager does not have the necessary time e.g., if they are busy managing the occurred problems. <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software<ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-27T10:45:07Z

S175068: /* Historical State of the Art */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. It also gives a guideline on how to get started using Gantt Charts as well as discussing the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added fetures<ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref><ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref><ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>. During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>.

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref> Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, if task 5 are dependent on task 4:
#Finish to start (FS), task 5 cannot start until task 4 is finished.
#Start to start (SS), task 5 cannot start until task 4 is started.
#Start to finish (SF), task 5 cannot be finished until task 4 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.

A variation of these is that there can be added a lead time or lag time one these dependencies. This will normally be done by e.g., FS+2days, this means that task 5 cannot start until 2 days later than task 4 is finished. An example is a wall that was cast and needs to dry for two days before it can be painted. The task ‘painting’ will have a lag time of 2 days on the finish to start dependency on ‘casting’. Dependency visualized in Microsoft project can be seen in figure 5.

[[File:Gantt Chart microsoft project dependency.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

[[File:Gantt Chart microsoft project progress.png|thumb|centre|500px|Figure 6: Progress in Microsoft Project, own creation]]

In figure 6 the progress can be seen as it is visualized in Microsoft Project, the middle of the bars change color. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget. <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support deapartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Guideline on how to get started using Gantt Charts =
'''Step 1:''' Decide on the level of detail.

'''Step 2:''' Decide on which tasks to include.

'''Step 3:''' Write the tasks in descending order in the column leftmost, from starting first to last.

'''Step 4:''' Select a start date.

'''Step 5:''' Ad duration for your tasks

'''Step 6:''' Add predecessors.

'''Step 7:''' Depending on the automation of your software, maybe start and finish for all some or all tasks are filled out, if not fill out the remaining.

'''Step 8:''' Add additional features you need like responsibility, resources, critical path, milestones, progress etc.

'''Step 9:''' Update the Gantt Chart during the execution of the project

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and be a disadvantage for the project manager.

there is a risk of the Gantt Chart getting overly complicated, if all minor tasks are added when they arise, it can confuse the users and be a disadvantage for the project manager. If the chart is unnecessarily complicated and a change happens in the project, there is a risk of the chart eventually ending outdated if the manager does not have the necessary time e.g., if they are busy managing the occurred problems. <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software<ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-27T10:44:49Z

S175068: /* Historical State of the Art */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. It also gives a guideline on how to get started using Gantt Charts as well as discussing the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added fetures<ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref><ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref><ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>. During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>.

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology <ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref> Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, if task 5 are dependent on task 4:
#Finish to start (FS), task 5 cannot start until task 4 is finished.
#Start to start (SS), task 5 cannot start until task 4 is started.
#Start to finish (SF), task 5 cannot be finished until task 4 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.

A variation of these is that there can be added a lead time or lag time one these dependencies. This will normally be done by e.g., FS+2days, this means that task 5 cannot start until 2 days later than task 4 is finished. An example is a wall that was cast and needs to dry for two days before it can be painted. The task ‘painting’ will have a lag time of 2 days on the finish to start dependency on ‘casting’. Dependency visualized in Microsoft project can be seen in figure 5.

[[File:Gantt Chart microsoft project dependency.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

[[File:Gantt Chart microsoft project progress.png|thumb|centre|500px|Figure 6: Progress in Microsoft Project, own creation]]

In figure 6 the progress can be seen as it is visualized in Microsoft Project, the middle of the bars change color. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget. <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support deapartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Guideline on how to get started using Gantt Charts =
'''Step 1:''' Decide on the level of detail.

'''Step 2:''' Decide on which tasks to include.

'''Step 3:''' Write the tasks in descending order in the column leftmost, from starting first to last.

'''Step 4:''' Select a start date.

'''Step 5:''' Ad duration for your tasks

'''Step 6:''' Add predecessors.

'''Step 7:''' Depending on the automation of your software, maybe start and finish for all some or all tasks are filled out, if not fill out the remaining.

'''Step 8:''' Add additional features you need like responsibility, resources, critical path, milestones, progress etc.

'''Step 9:''' Update the Gantt Chart during the execution of the project

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and be a disadvantage for the project manager.

there is a risk of the Gantt Chart getting overly complicated, if all minor tasks are added when they arise, it can confuse the users and be a disadvantage for the project manager. If the chart is unnecessarily complicated and a change happens in the project, there is a risk of the chart eventually ending outdated if the manager does not have the necessary time e.g., if they are busy managing the occurred problems. <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software<ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-27T10:42:40Z

S175068: /* Gantt Chart in Project Management */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. It also gives a guideline on how to get started using Gantt Charts as well as discussing the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used both in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added fetures<ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref><ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref><ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref> During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user. <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company. <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref> Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, if task 5 are dependent on task 4:
#Finish to start (FS), task 5 cannot start until task 4 is finished.
#Start to start (SS), task 5 cannot start until task 4 is started.
#Start to finish (SF), task 5 cannot be finished until task 4 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.

A variation of these is that there can be added a lead time or lag time one these dependencies. This will normally be done by e.g., FS+2days, this means that task 5 cannot start until 2 days later than task 4 is finished. An example is a wall that was cast and needs to dry for two days before it can be painted. The task ‘painting’ will have a lag time of 2 days on the finish to start dependency on ‘casting’. Dependency visualized in Microsoft project can be seen in figure 5.

[[File:Gantt Chart microsoft project dependency.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

[[File:Gantt Chart microsoft project progress.png|thumb|centre|500px|Figure 6: Progress in Microsoft Project, own creation]]

In figure 6 the progress can be seen as it is visualized in Microsoft Project, the middle of the bars change color. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget. <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support deapartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Guideline on how to get started using Gantt Charts =
'''Step 1:''' Decide on the level of detail.

'''Step 2:''' Decide on which tasks to include.

'''Step 3:''' Write the tasks in descending order in the column leftmost, from starting first to last.

'''Step 4:''' Select a start date.

'''Step 5:''' Ad duration for your tasks

'''Step 6:''' Add predecessors.

'''Step 7:''' Depending on the automation of your software, maybe start and finish for all some or all tasks are filled out, if not fill out the remaining.

'''Step 8:''' Add additional features you need like responsibility, resources, critical path, milestones, progress etc.

'''Step 9:''' Update the Gantt Chart during the execution of the project

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and be a disadvantage for the project manager.

there is a risk of the Gantt Chart getting overly complicated, if all minor tasks are added when they arise, it can confuse the users and be a disadvantage for the project manager. If the chart is unnecessarily complicated and a change happens in the project, there is a risk of the chart eventually ending outdated if the manager does not have the necessary time e.g., if they are busy managing the occurred problems. <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software<ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-27T10:41:25Z

S175068: /* Abstract */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependencies, critical paths, responsibilities, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. It also gives a guideline on how to get started using Gantt Charts as well as discussing the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used but in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependency, critical path, responsibility, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added fetures<ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref><ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref><ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref> During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user. <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company. <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref> Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, if task 5 are dependent on task 4:
#Finish to start (FS), task 5 cannot start until task 4 is finished.
#Start to start (SS), task 5 cannot start until task 4 is started.
#Start to finish (SF), task 5 cannot be finished until task 4 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.

A variation of these is that there can be added a lead time or lag time one these dependencies. This will normally be done by e.g., FS+2days, this means that task 5 cannot start until 2 days later than task 4 is finished. An example is a wall that was cast and needs to dry for two days before it can be painted. The task ‘painting’ will have a lag time of 2 days on the finish to start dependency on ‘casting’. Dependency visualized in Microsoft project can be seen in figure 5.

[[File:Gantt Chart microsoft project dependency.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

[[File:Gantt Chart microsoft project progress.png|thumb|centre|500px|Figure 6: Progress in Microsoft Project, own creation]]

In figure 6 the progress can be seen as it is visualized in Microsoft Project, the middle of the bars change color. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget. <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support deapartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Guideline on how to get started using Gantt Charts =
'''Step 1:''' Decide on the level of detail.

'''Step 2:''' Decide on which tasks to include.

'''Step 3:''' Write the tasks in descending order in the column leftmost, from starting first to last.

'''Step 4:''' Select a start date.

'''Step 5:''' Ad duration for your tasks

'''Step 6:''' Add predecessors.

'''Step 7:''' Depending on the automation of your software, maybe start and finish for all some or all tasks are filled out, if not fill out the remaining.

'''Step 8:''' Add additional features you need like responsibility, resources, critical path, milestones, progress etc.

'''Step 9:''' Update the Gantt Chart during the execution of the project

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and be a disadvantage for the project manager.

there is a risk of the Gantt Chart getting overly complicated, if all minor tasks are added when they arise, it can confuse the users and be a disadvantage for the project manager. If the chart is unnecessarily complicated and a change happens in the project, there is a risk of the chart eventually ending outdated if the manager does not have the necessary time e.g., if they are busy managing the occurred problems. <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software<ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Corrective and Preventive Actions (CAPA)

2021-02-26T13:18:37Z

S175068: /* Regulatory authorities */

=Abstract=

Corrective and Preventive Actions (CAPA) are procedures designed to handle nonconformity and other undesirable situations. In this context is corrective actions is defined as actions set in motion to eliminate an occurred nonconformities or unwanted situations, and preventive actions as actions set in motion to eliminate potential nonconformities or unwanted situations <ref name="CAPAFDA">Rodríguez-Pérez, José American Society for Quality 2011, CAPA for the FDA Regulated Industry</ref>. CAPA is a mandatory part of the Quality Management System (QMS) for any pharmaceutical or medical device manufacturer reporting to the U.S Food and Drug Administration (FDA). CAPA is also an integrated part of ISO:13485 and Good Manufacturing Practice (GMP) for medical products. The FDA defines the purpose of a CAPA procedure as: collecting and analyzing information, identifying and investigating product and quality problems, and taking appropriate and effective corrective and/or preventive action to prevent their recurrence <ref name="FDA">FDA website Corrective and Preventive Actions (CAPA). Link: https://www.fda.gov/corrective-and-preventive-actions-capa#page3.</ref>

The purpose of this article is to give the reader an overview on how to perform a CAPA and which risk to be aware of. In this article a 7 step framework is presented. The steps include 1) Identification; 2) Evaluation; 3) Investigation; 4) Analysis; 5) Action Plan; 6) Implementation; 7) Follow-up.

=The context of CAPA=

===Project quality management===

A project is an unique temporary organizational construction with a defined objective. Projects can operate under different constrains such as time, cost, quality, etc. CAPA projects are related to quality management of a product/system. Quality management is the coordinating of activities to direct and control an organization with regard to quality. The CAPA process can be used as a quality management approach when working with project management. A quality management approach is a procedure that describes how quality will be managed in a given project <ref name="AXELOS">AXELOS, Managing Successful Projects with PRINCE2 2017 Edition chapter 8</ref>.
====Continuous improvement====
CAPA is categorized under the section measurement, analysis and improvement in ISO:13485 and closely related to continues improvement processes. CAPA can be an alternative to processes such as the plan-do-check-act (PDCA) by Shewhart (modified by Deming), or other quality improvement initiatives such as total quality management (TQM), Six Sigma, and Lean <ref name="AXELOS">AXELOS, Managing Successful Projects with PRINCE2 2017 Edition chapter 8</ref>.
===Regulatory authorities===
CAPA is most commonly used in highly regulatory industries and is a mandatory part of a Quality Management System (QMS) for any pharmaceutical or medical device manufacturer reporting to the U.S Food and Drug Administration (FDA) or who is compliant with ISO:13485 Medical Devices as well as European Pharmaceutical GMP and IATF. Procedures for corrective actions is also mandatory to include in the QMS for the majority of ISO management systems.
[[File:CAPA.PNG|800px|thumb|centre|Figure 1: Corrective action vs. preventive action <ref name="Mark">Hammar, Mark
Complete guide to corrective action vs. preventive action. Link: https://advisera.com/9001academy/blog/2020/06/22/complete-guide-to-corrective-action-vs-preventive-action/</ref>]]

The FDA require that CAPA procedure includes:
* identifying existing and potential causes of nonconforming product, or other quality problems;
* identifying the cause of nonconformities relating to product, processes, and the quality system;
* identifying action(s) necessary to correct and prevent a recurrence of the problem(s);
* verifying/validating the corrective and/or preventive action(s);
* implementing and recording change needed to correct and prevent the identified problem(s);
* ensuring information related to the problem is shared with those directly responsible for assuring the quality;
* summitting relevant information for the management review;
* all activities above and their results, shall be documented <ref name="FDA2">FDA, 2020 CFR - Code of Federal Regulations. Link: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=820.100</ref>.

The ISO:13485 requirements is somewhat similar to the FDA. The CAPA should system includes procedures for: reviewing nonconformities, finding the root cause of the problem or determining potential nonconformites, evaluate the need for action to eliminate the nonconformity, plan and document action implemented, verifying the action does not adversely affect the ability to meet applicable regulatory requirements or the safety and performance of the product, and reviewing the effectiveness of corrective or preventive action taken [ISO:13484].

{| class="wikitable"
|-
!
!Corrective Action
!Preventive Action
|-
| Type of activity
| Reactive
| Proactive
|-
| Role in ISO 13485, FDA, IATF 16949, European Pharmaceutical GMP
| Assessment of root cause and action plan to prevent recurrence
| Assessment of root cause and action plan to prevent recurrence
|-
| The majority of ISO management system standards
| Assessment of root cause and action plan to prevent recurrence
| Replaced by risk-based thinking and improvement.
|}

=The purpose of an efficient CAPA process=

CAPA is designed to ensure quality and continuous improvement, which is especially important in the pharmaceutical and medicine device industry since lack of control can have fatal consequences. CAPA is one of the most essential regulatory area for both the FDA and ISO in pharmaceutical quality systems and industries producing medical devices <ref name="FDA">FDA website Corrective and Preventive Actions (CAPA). Link: https://www.fda.gov/corrective-and-preventive-actions-capa#page3.</ref>, <ref name="9steps">Rodriguez, Jackelyn. CAPA in the Pharmaceutical and Biotech Industries – How to Implement an Effective Nine Step Program 2016, Woodhead publishing series in biomedicine </ref>. The CAPA system is practically always a part of the regulatory compliance audit and around 30-50 percent of nonconformance cited by the FDA is due to inadequate performance of CAPA. In the worst case can the FDA withdraw their certification, which is necessary to sell production on the U.S market. The CAPA process is more demanding and rigid than other similar approaches such as the PDCA. This is to ensure that all regulatory demands are fulfilled <ref name="CAPAFDA">Rodríguez-Pérez, José American Society for Quality 2011, CAPA for the FDA Regulated Industry</ref>.

= The 7 steps of CAPA =
The CAPA process is typically divided into 5-9 steps depending on the scope of the steps. In this article a 7 step framework is introduced. The steps include 1) Identification; 2) Evaluation; 3) Investigation; 4) Analysis; 5) Action Plan; 6) Implementation; 7) Follow-up. When CAPA is performed as a part of a regulatory requirement such as FDA or ISO:13845 documentation through each step is crucial.

===Step 1: Identification===
The first step of the CAPA process is to identifying, describe and document the problem. A nonconformity incident does not necessarily trigger a CAPA. However it is necessary to evaluated every nonconformance and assess what action is appropriate. Nonconformance can be identified from both internal and external sources, including, but not limited to:
*service request;
*internal quality audits;
*costumer complaints;
*quality assurance inspections;
*staff observation;
*trending data;
*risk assessment;
*management review;
*failure mode analysis;
*Audit findings <ref name="MasterControl">Simplifying CAPA: Seven Steps to a Comprehensive CAPA Plan 2019 MasterControl. Link:
https://www.mastercontrol.com/learning-center/capa-management/simplifying-capa-seven-steps.</ref>. <ref name="Review">Abhishek, Raj. 2016 A review on corrective action and preventive action (CAPA) Deputy R&D Manager, Quest Pharmaceuticals Pvt. Ltd, Chhata Pipara, Bara, Birgunj, Nepal. Link: https://academicjournals.org/journal/AJPP/article-full-text-pdf/4EF704756791</ref>.

When a problem is discovered, a clear problem statement should be written. It is important to precisely and completely describe the situation. The problem statement should include the source of the information, evidence of the problem and a detailed explanation of the problem <ref name="MasterControl">Simplifying CAPA: Seven Steps to a Comprehensive CAPA Plan 2019 MasterControl. Link:
https://www.mastercontrol.com/learning-center/capa-management/simplifying-capa-seven-steps.</ref>. Here answering the following questions can be helpful.
[[File:CAPA2.PNG|600px|thumb|centre|Figure 2: How to identify the problem <ref name="Root">Okes, Duke 2009. Root Cause Analysis – The core of Problem Solving and Corrective Action. ASQ Quality Press.</ref>]]
Information about the problem will often be provided form different parts of the organization, and it can therefore be helpful to develop a standard procedure for collecting this data, and trying to reduce the work load for the employees<ref name="Root">Okes, Duke 2009. Root Cause Analysis – The core of Problem Solving and Corrective Action. ASQ Quality Press.</ref>.
A well-defined problem statement is essential for the later work and the effectiveness of the CAPA process <ref name="9steps">Rodriguez, Jackelyn. CAPA in the Pharmaceutical and Biotech Industries – How to Implement an Effective Nine Step Program 2016, Woodhead publishing series in biomedicine </ref>. As the cited quote from Charles Kettering emphasizes “a problem well-stated is a problem half-solved”.

===Step 2: Evaluation===
In step 2 the problem is evaluated to determine why the problem is a concern, and the impact and risk associated with the problem. This can be the possible impact on costs, function, product quality, safety, reliability, customer satisfaction, etc. <ref name="9steps">Rodriguez, Jackelyn. CAPA in the Pharmaceutical and Biotech Industries – How to Implement an Effective Nine Step Program 2016, Woodhead publishing series in biomedicine </ref>. The risks can be evaluated based on the probability/impact matrix.
[[File:CAPA3.PNG|400px|thumb|centre|Figure 3: The probability/impact matrix </ref>, <ref name="9steps">Rodriguez, Jackelyn. CAPA in the Pharmaceutical and Biotech Industries – How to Implement an Effective Nine Step Program 2016, Woodhead publishing series in biomedicine </ref>]]

The evaluation is used to decide the priority of the actions as well as the level of investigation. It makes it possible for management to better prioritize encountered complaints, deviations, nonconformance, corrections, and removals <ref name="9steps">Rodriguez, Jackelyn. CAPA in the Pharmaceutical and Biotech Industries – How to Implement an Effective Nine Step Program 2016, Woodhead publishing series in biomedicine </ref>. In some cases immediate corrective action is necessary until a thorough investigation have been conducted and permanent solutions have been implemented. The immediate corrective actions can in some cases be enough to correct the problem which eliminate the need for step 5 and 6 <ref name="MasterControl">Simplifying CAPA: Seven Steps to a Comprehensive CAPA Plan 2019 MasterControl. Link:
https://www.mastercontrol.com/learning-center/capa-management/simplifying-capa-seven-steps.</ref>. In other cases, it is assessed that no action is required. If this is the conclusion a justification must be documented.

[http://apppm.man.dtu.dk/index.php/Impact_and_Probability_in_Risk_Assessment Read more about impact and probability in risk assessment here]

===Step 3: Investigation===
In step 3 a procedure for the investigation (analysis) if formulated. High-risk investigations will have priority over low-risk situations <ref name="CAPAFDA">Rodríguez-Pérez, José American Society for Quality 2011, CAPA for the FDA Regulated Industry</ref>. The purpose of the procedure is to ensure that noting is overlooked in the investigation. The procedure should include information about, but not limited to: the objective for the actions, which resources is required (money, time, testing equipment, personnel, etc.), who is responsible for conducting the investigation, which data is collected, and instructions for determining the causes of the problem including a timeline <ref name="9steps">Rodriguez, Jackelyn. CAPA in the Pharmaceutical and Biotech Industries – How to Implement an Effective Nine Step Program 2016, Woodhead publishing series in biomedicine </ref>, <ref name="MasterControl">Simplifying CAPA: Seven Steps to a Comprehensive CAPA Plan 2019 MasterControl. Link:
https://www.mastercontrol.com/learning-center/capa-management/simplifying-capa-seven-steps.</ref>. The procedure require a review of all circumstances related to the problem and must consider the following:
*External factors
*Software
*Training
*Design
*Procedures
*Personnel
*Materials
*Equipment
The level of investigation is determined based on the risk evaluation results or trend analysis results <ref name="9steps">Rodriguez, Jackelyn. CAPA in the Pharmaceutical and Biotech Industries – How to Implement an Effective Nine Step Program 2016, Woodhead publishing series in biomedicine </ref>.

===Step 4: Analysis===
In step 4 the investigation procedure is used to investigate the root cause of the problem as well as other contributing factors. This is done by collecting all relevant data and investigating all possible causes through a Root Cause Analysis (RCA). A RCA is a systematic approach to finding the underling (main) cause of a problem. When a root cause is proper managed the problem stops recurring <ref name="9steps">Rodriguez, Jackelyn. CAPA in the Pharmaceutical and Biotech Industries – How to Implement an Effective Nine Step Program 2016, Woodhead publishing series in biomedicine </ref>. Different tools can be used to support this step. The most typical tools include, 5xwhy and fishbone diagram.
Five whys is a simple and very popular tool for RCA. To find the root cause one has to ask what cause the problem, and question the answer five times<ref name="5xwhys">Serrat, Olivier, 2017, The Five Whys Technique, Knowledge Solutions.</ref>.
[[File:CAPA4.PNG|400px|thumb|centre|Figure 4: The 5xwhys<ref name="5xwhys">Serrat, Olivier, 2017, The Five Whys Technique, Knowledge Solutions.</ref>]]
The five whys approach can quickly be adapted and applied to most problems. There are three fundamental elements to effectively using the five whys: 1) a good clear statement; 2) honesty and competencies to answer the questions; 3) determination to find the problem<ref name="5xwhys">Serrat, Olivier, 2017, The Five Whys Technique, Knowledge Solutions.</ref>.
The second method is the fishbone diagram (also known as the cause and effect diagram), which can be used by itself or together with the five whys. The fishbone diagram is used to identify different elements that could be the root cause, divided into different areas. The fishbone diagram are useful if many factors affect the problem <ref name="Root">Okes, Duke 2009. Root Cause Analysis – The core of Problem Solving and Corrective Action. ASQ Quality Press.</ref>.
[[File:CAPA5.PNG|400px|thumb|centre|Figure 5: fishbone diagram<ref name="KS">Jensen, Torben Jul 2005 Kvalitetsstyring og måleteknik (quality management and measurement technology).</ref>]]

===Step 5: Action plan===
When the root cause is identified an action plan needs to be developed. The action plan determine what actions will be initiated, how, by who, when and so on. The documentation of that actions are initiated is important to have an effective follow-up <ref name="9steps">Rodriguez, Jackelyn. CAPA in the Pharmaceutical and Biotech Industries – How to Implement an Effective Nine Step Program 2016, Woodhead publishing series in biomedicine </ref>. Examples of actions that can be initiated includes: documentation/forms/instruction changes; procedure changes; employee training; or new equipment. A monitoring system or controls also need to be implemented to prevent the problem for recurrent.
[[File:CAPA6.PNG|400px|thumb|centre|Figure 6: corrective/preventive action plan <ref name="9steps">Rodriguez, Jackelyn. CAPA in the Pharmaceutical and Biotech Industries – How to Implement an Effective Nine Step Program 2016, Woodhead publishing series in biomedicine </ref>]]
The degree of corrective and preventive action taken to eliminate or minimize actual or potential non-conformities must be appropriate to the magnitude of the problem and commensurate with the risks encountered <ref name="Review">Abhishek, Raj. 2016 A review on corrective action and preventive action (CAPA) Deputy R&D Manager, Quest Pharmaceuticals Pvt. Ltd, Chhata Pipara, Bara, Birgunj, Nepal. Link: https://academicjournals.org/journal/AJPP/article-full-text-pdf/4EF704756791</ref>. It is necessary to validate that the proposed corrective and/or preventive actions will achieving the desired results<ref name="CAPAFDA">Rodríguez-Pérez, José American Society for Quality 2011, CAPA for the FDA Regulated Industry</ref>.

===Step 6: Implementation===
In step 6 the action plan is implemented. Documentation of each implementations is important to ensure all actions are completed. The documentation should be attached to a final report of this CAPA action. When a plan has been completed all activities should be verified by ta independent party from the individual having completed the task <ref name="9steps">Rodriguez, Jackelyn. CAPA in the Pharmaceutical and Biotech Industries – How to Implement an Effective Nine Step Program 2016, Woodhead publishing series in biomedicine </ref>.
A frequent problem observed by the FDA is that the corrective and preventive actions were not implemented. It is therefore important to appoint to define clear responsibility’s and apply a tracking system that can verify the implementation <ref name="CAPAFDA">Rodríguez-Pérez, José American Society for Quality 2011, CAPA for the FDA Regulated Industry</ref>.

===Step 7: Follow-up===
The last step of the CAPA process is a follow-up where the corrective or preventive actions is evaluated. The purpose of this step is to check that all changes have been implemented and verified <ref name="9steps">Rodriguez, Jackelyn. CAPA in the Pharmaceutical and Biotech Industries – How to Implement an Effective Nine Step Program 2016, Woodhead publishing series in biomedicine </ref>.

= Limitations =
*'''Resource demanding process:''' The CAPA process is a resource demanding process and is most suited for highly regulatory industries where documentation, validation and procedures is extremely controlled.

*'''The success of the CAPA depends on a lot of different factors:''' The success of the process is depending on a lot of other procedures in the company. This means that even if a suitable CAPA procedure is in place the outcome is not always useful.

*'''Correcting the symptoms instead of the cause:''' A typical problems in the CAPA process is that a symptom is fixed instead of the real root cause. A common mistake is to point to a human error as the root cause when this is merely a symptom.

*'''Root cause identified but not corrected:''' Another typical mistake is that a root cause is identified but not corrected. This can be due to lack of control and follow-up. The problem can also arise by following the Pareto principle and only fixing the prominent cause and not solving the problem.

=Other relevant Wiki articles=
'''How to create a working CAPA team:''' [http://wiki.doing-projects.org/index.php/Roles_and_responsibilities_in_project_team Roles and responsibilities in project team.]

'''How to control the scope of the CAPA project:''' [http://wiki.doing-projects.org/index.php/Project_Scope_Management Project Scope Management.]

'''How to ensure control of the CAPA process:''' [http://wiki.doing-projects.org/index.php/Project_Control Project Control.]

'''How to improve your CAPA processes:''' [http://wiki.doing-projects.org/index.php/Lessons_learned Lessons learned.]

=Annotated Bibliography=

CAPA for the FDA Regulated Industry, José Rodríguez-Pérez, 2011. This book contains a guidance to execute and improve the CAPA system. The book have focus on the FDA regulatory requirement, but include other regulatory areas such as ISO.

CAPA in the Pharmaceutical and Biotech Industries – How to Implement an Effective Nine Step Program, Jackelyn Rodriguez, 2016. This book contains information on how to implement, develop and maintain an effective CAPA system and investigation program using a 9-step for medical device, pharmaceutical and biologic manufacturers, as well as any company or institution, which has to maintain a quality system.

FDA website Corrective and Preventive Actions (CAPA). The FDA website have public information about what elements should be included in the CAPA process.

Root Cause Analysis – The core of Problem Solving and Corrective Action, Duke Okes 2019. In this book different methods to identifying and execute corrective actions is described.

= References =
<references/>

Gantt Charts

2021-02-26T12:43:21Z

S175068: /* Dependency */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependency, critical path, responsibility, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. It also gives a guideline on how to get started using Gantt Charts as well as discussing the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used but in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependency, critical path, responsibility, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added fetures<ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref><ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref><ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref> During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user. <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company. <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref> Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, if task 5 are dependent on task 4:
#Finish to start (FS), task 5 cannot start until task 4 is finished.
#Start to start (SS), task 5 cannot start until task 4 is started.
#Start to finish (SF), task 5 cannot be finished until task 4 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.

A variation of these is that there can be added a lead time or lag time one these dependencies. This will normally be done by e.g., FS+2days, this means that task 5 cannot start until 2 days later than task 4 is finished. An example is a wall that was cast and needs to dry for two days before it can be painted. The task ‘painting’ will have a lag time of 2 days on the finish to start dependency on ‘casting’. Dependency visualized in Microsoft project can be seen in figure 5.

[[File:Gantt Chart microsoft project dependency.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

[[File:Gantt Chart microsoft project progress.png|thumb|centre|500px|Figure 6: Progress in Microsoft Project, own creation]]

In figure 6 the progress can be seen as it is visualized in Microsoft Project, the middle of the bars change color. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget. <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support deapartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Guideline on how to get started using Gantt Charts =
'''Step 1:''' Decide on the level of detail.

'''Step 2:''' Decide on which tasks to include.

'''Step 3:''' Write the tasks in descending order in the column leftmost, from starting first to last.

'''Step 4:''' Select a start date.

'''Step 5:''' Ad duration for your tasks

'''Step 6:''' Add predecessors.

'''Step 7:''' Depending on the automation of your software, maybe start and finish for all some or all tasks are filled out, if not fill out the remaining.

'''Step 8:''' Add additional features you need like responsibility, resources, critical path, milestones, progress etc.

'''Step 9:''' Update the Gantt Chart during the execution of the project

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and be a disadvantage for the project manager.

there is a risk of the Gantt Chart getting overly complicated, if all minor tasks are added when they arise, it can confuse the users and be a disadvantage for the project manager. If the chart is unnecessarily complicated and a change happens in the project, there is a risk of the chart eventually ending outdated if the manager does not have the necessary time e.g., if they are busy managing the occurred problems. <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software<ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-26T12:42:57Z

S175068: /* Milestones */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependency, critical path, responsibility, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. It also gives a guideline on how to get started using Gantt Charts as well as discussing the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used but in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependency, critical path, responsibility, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added fetures<ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref><ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref><ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref> During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user. <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company. <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|500px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref> Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, if task 5 are dependent on task 4:
#Finish to start (FS), task 5 cannot start until task 4 is finished.
#Start to start (SS), task 5 cannot start until task 4 is started.
#Start to finish (SF), task 5 cannot be finished until task 4 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.

[[File:Gantt Chart microsoft project dependency.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

A variation of these is that there can be added a lead time or lag time one these dependencies. This will normally be done by e.g., FS+2days, this means that task 5 cannot start until 2 days later than task 4 is finished. An example is a wall that was cast and needs to dry for two days before it can be painted. The task ‘painting’ will have a lag time of 2 days on the finish to start dependency on ‘casting’. Dependency visualized in Microsoft project can be seen in figure 5.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

[[File:Gantt Chart microsoft project progress.png|thumb|centre|500px|Figure 6: Progress in Microsoft Project, own creation]]

In figure 6 the progress can be seen as it is visualized in Microsoft Project, the middle of the bars change color. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget. <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support deapartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Guideline on how to get started using Gantt Charts =
'''Step 1:''' Decide on the level of detail.

'''Step 2:''' Decide on which tasks to include.

'''Step 3:''' Write the tasks in descending order in the column leftmost, from starting first to last.

'''Step 4:''' Select a start date.

'''Step 5:''' Ad duration for your tasks

'''Step 6:''' Add predecessors.

'''Step 7:''' Depending on the automation of your software, maybe start and finish for all some or all tasks are filled out, if not fill out the remaining.

'''Step 8:''' Add additional features you need like responsibility, resources, critical path, milestones, progress etc.

'''Step 9:''' Update the Gantt Chart during the execution of the project

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and be a disadvantage for the project manager.

there is a risk of the Gantt Chart getting overly complicated, if all minor tasks are added when they arise, it can confuse the users and be a disadvantage for the project manager. If the chart is unnecessarily complicated and a change happens in the project, there is a risk of the chart eventually ending outdated if the manager does not have the necessary time e.g., if they are busy managing the occurred problems. <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software<ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-26T12:42:00Z

S175068: /* Abstract */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=

[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependency, critical path, responsibility, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. It also gives a guideline on how to get started using Gantt Charts as well as discussing the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used but in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependency, critical path, responsibility, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added fetures<ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref><ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref><ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref> During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user. <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company. <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|200px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref> Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, if task 5 are dependent on task 4:
#Finish to start (FS), task 5 cannot start until task 4 is finished.
#Start to start (SS), task 5 cannot start until task 4 is started.
#Start to finish (SF), task 5 cannot be finished until task 4 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.

[[File:Gantt Chart microsoft project dependency.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

A variation of these is that there can be added a lead time or lag time one these dependencies. This will normally be done by e.g., FS+2days, this means that task 5 cannot start until 2 days later than task 4 is finished. An example is a wall that was cast and needs to dry for two days before it can be painted. The task ‘painting’ will have a lag time of 2 days on the finish to start dependency on ‘casting’. Dependency visualized in Microsoft project can be seen in figure 5.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

[[File:Gantt Chart microsoft project progress.png|thumb|centre|500px|Figure 6: Progress in Microsoft Project, own creation]]

In figure 6 the progress can be seen as it is visualized in Microsoft Project, the middle of the bars change color. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget. <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support deapartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Guideline on how to get started using Gantt Charts =
'''Step 1:''' Decide on the level of detail.

'''Step 2:''' Decide on which tasks to include.

'''Step 3:''' Write the tasks in descending order in the column leftmost, from starting first to last.

'''Step 4:''' Select a start date.

'''Step 5:''' Ad duration for your tasks

'''Step 6:''' Add predecessors.

'''Step 7:''' Depending on the automation of your software, maybe start and finish for all some or all tasks are filled out, if not fill out the remaining.

'''Step 8:''' Add additional features you need like responsibility, resources, critical path, milestones, progress etc.

'''Step 9:''' Update the Gantt Chart during the execution of the project

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and be a disadvantage for the project manager.

there is a risk of the Gantt Chart getting overly complicated, if all minor tasks are added when they arise, it can confuse the users and be a disadvantage for the project manager. If the chart is unnecessarily complicated and a change happens in the project, there is a risk of the chart eventually ending outdated if the manager does not have the necessary time e.g., if they are busy managing the occurred problems. <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software<ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-26T12:37:35Z

S175068: /* Dependency */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=
[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependency, critical path, responsibility, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. It also gives a guideline on how to get started using Gantt Charts as well as discussing the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used but in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependency, critical path, responsibility, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added fetures<ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref><ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref><ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref> During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user. <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company. <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|200px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref> Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

There are generally four ways of describing dependency<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, if task 5 are dependent on task 4:
#Finish to start (FS), task 5 cannot start until task 4 is finished.
#Start to start (SS), task 5 cannot start until task 4 is started.
#Start to finish (SF), task 5 cannot be finished until task 4 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.

[[File:Gantt Chart microsoft project dependency.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

A variation of these is that there can be added a lead time or lag time one these dependencies. This will normally be done by e.g., FS+2days, this means that task 5 cannot start until 2 days later than task 4 is finished. An example is a wall that was cast and needs to dry for two days before it can be painted. The task ‘painting’ will have a lag time of 2 days on the finish to start dependency on ‘casting’. Dependency visualized in Microsoft project can be seen in figure 5.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

[[File:Gantt Chart microsoft project progress.png|thumb|centre|500px|Figure 6: Progress in Microsoft Project, own creation]]

In figure 6 the progress can be seen as it is visualized in Microsoft Project, the middle of the bars change color. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget. <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support deapartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Guideline on how to get started using Gantt Charts =
'''Step 1:''' Decide on the level of detail.

'''Step 2:''' Decide on which tasks to include.

'''Step 3:''' Write the tasks in descending order in the column leftmost, from starting first to last.

'''Step 4:''' Select a start date.

'''Step 5:''' Ad duration for your tasks

'''Step 6:''' Add predecessors.

'''Step 7:''' Depending on the automation of your software, maybe start and finish for all some or all tasks are filled out, if not fill out the remaining.

'''Step 8:''' Add additional features you need like responsibility, resources, critical path, milestones, progress etc.

'''Step 9:''' Update the Gantt Chart during the execution of the project

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and be a disadvantage for the project manager.

there is a risk of the Gantt Chart getting overly complicated, if all minor tasks are added when they arise, it can confuse the users and be a disadvantage for the project manager. If the chart is unnecessarily complicated and a change happens in the project, there is a risk of the chart eventually ending outdated if the manager does not have the necessary time e.g., if they are busy managing the occurred problems. <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software<ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-26T12:36:37Z

S175068: /* Features of the Gantt Chart */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=
[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependency, critical path, responsibility, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. It also gives a guideline on how to get started using Gantt Charts as well as discussing the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used but in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependency, critical path, responsibility, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added fetures<ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref><ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref><ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref> During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user. <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company. <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|200px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref> Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

[[File:Gantt Chart microsoft project dependency.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

There are generally four ways of describing dependency<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, if task 5 are dependent on task 4:
#Finish to start (FS), task 5 cannot start until task 4 is finished.
#Start to start (SS), task 5 cannot start until task 4 is started.
#Start to finish (SF), task 5 cannot be finished until task 4 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.

A variation of these is that there can be added a lead time or lag time one these dependencies. This will normally be done by e.g., FS+2days, this means that task 5 cannot start until 2 days later than task 4 is finished. An example is a wall that was cast and needs to dry for two days before it can be painted. The task ‘painting’ will have a lag time of 2 days on the finish to start dependency on ‘casting’. Dependency visualized in Microsoft project can be seen in figure 5.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===
The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress.

[[File:Gantt Chart microsoft project progress.png|thumb|centre|500px|Figure 6: Progress in Microsoft Project, own creation]]

In figure 6 the progress can be seen as it is visualized in Microsoft Project, the middle of the bars change color. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget. <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support deapartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Guideline on how to get started using Gantt Charts =
'''Step 1:''' Decide on the level of detail.

'''Step 2:''' Decide on which tasks to include.

'''Step 3:''' Write the tasks in descending order in the column leftmost, from starting first to last.

'''Step 4:''' Select a start date.

'''Step 5:''' Ad duration for your tasks

'''Step 6:''' Add predecessors.

'''Step 7:''' Depending on the automation of your software, maybe start and finish for all some or all tasks are filled out, if not fill out the remaining.

'''Step 8:''' Add additional features you need like responsibility, resources, critical path, milestones, progress etc.

'''Step 9:''' Update the Gantt Chart during the execution of the project

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and be a disadvantage for the project manager.

there is a risk of the Gantt Chart getting overly complicated, if all minor tasks are added when they arise, it can confuse the users and be a disadvantage for the project manager. If the chart is unnecessarily complicated and a change happens in the project, there is a risk of the chart eventually ending outdated if the manager does not have the necessary time e.g., if they are busy managing the occurred problems. <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software<ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-26T10:41:18Z

S175068: /* Limitations of the Gantt Chart */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=
[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependency, critical path, responsibility, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. It also gives a guideline on how to get started using Gantt Charts as well as discussing the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used but in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependency, critical path, responsibility, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added fetures<ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref><ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref><ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref> During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user. <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company. <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|200px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref> Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

[[File:Gantt Chart microsoft project dependency.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

There are generally four ways of describing dependency<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, if task 5 are dependent on task 4:
#Finish to start (FS), task 5 cannot start until task 4 is finished.
#Start to start (SS), task 5 cannot start until task 4 is started.
#Start to finish (SF), task 5 cannot be finished until task 4 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.

A variation of these is that there can be added a lead time or lag time one these dependencies. This will normally be done by e.g., FS+2days, this means that task 5 cannot start until 2 days later than task 4 is finished. An example is a wall that was cast and needs to dry for two days before it can be painted. The task ‘painting’ will have a lag time of 2 days on the finish to start dependency on ‘casting’. Dependency visualized in Microsoft project can be seen in figure 5.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===

[[File:Gantt Chart microsoft project progress.png|thumb|250px|Figure 6: Progress in Microsoft Project, own creation]]

The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress. In figure 6 the progress can be seen as it is visualized in Microsoft Project, the middle of the bars change color. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget. <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support deapartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Guideline on how to get started using Gantt Charts =
'''Step 1:''' Decide on the level of detail.

'''Step 2:''' Decide on which tasks to include.

'''Step 3:''' Write the tasks in descending order in the column leftmost, from starting first to last.

'''Step 4:''' Select a start date.

'''Step 5:''' Ad duration for your tasks

'''Step 6:''' Add predecessors.

'''Step 7:''' Depending on the automation of your software, maybe start and finish for all some or all tasks are filled out, if not fill out the remaining.

'''Step 8:''' Add additional features you need like responsibility, resources, critical path, milestones, progress etc.

'''Step 9:''' Update the Gantt Chart during the execution of the project

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects, but a Gantt Chart can be confusing to understand if too many minor tasks are added. Adding too many insignificant tasks can make the Gantt Chart overly complicated and be a disadvantage for the project manager.

there is a risk of the Gantt Chart getting overly complicated, if all minor tasks are added when they arise, it can confuse the users and be a disadvantage for the project manager. If the chart is unnecessarily complicated and a change happens in the project, there is a risk of the chart eventually ending outdated if the manager does not have the necessary time e.g., if they are busy managing the occurred problems. <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software<ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-26T10:35:41Z

S175068: /* Limitations of the Gantt Chart */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=
[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependency, critical path, responsibility, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. It also gives a guideline on how to get started using Gantt Charts as well as discussing the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used but in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependency, critical path, responsibility, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added fetures<ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref><ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref><ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref> During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user. <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company. <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|200px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref> Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

[[File:Gantt Chart microsoft project dependency.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

There are generally four ways of describing dependency<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, if task 5 are dependent on task 4:
#Finish to start (FS), task 5 cannot start until task 4 is finished.
#Start to start (SS), task 5 cannot start until task 4 is started.
#Start to finish (SF), task 5 cannot be finished until task 4 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.

A variation of these is that there can be added a lead time or lag time one these dependencies. This will normally be done by e.g., FS+2days, this means that task 5 cannot start until 2 days later than task 4 is finished. An example is a wall that was cast and needs to dry for two days before it can be painted. The task ‘painting’ will have a lag time of 2 days on the finish to start dependency on ‘casting’. Dependency visualized in Microsoft project can be seen in figure 5.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===

[[File:Gantt Chart microsoft project progress.png|thumb|250px|Figure 6: Progress in Microsoft Project, own creation]]

The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress. In figure 6 the progress can be seen as it is visualized in Microsoft Project, the middle of the bars change color. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget. <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support deapartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Guideline on how to get started using Gantt Charts =
'''Step 1:''' Decide on the level of detail.

'''Step 2:''' Decide on which tasks to include.

'''Step 3:''' Write the tasks in descending order in the column leftmost, from starting first to last.

'''Step 4:''' Select a start date.

'''Step 5:''' Ad duration for your tasks

'''Step 6:''' Add predecessors.

'''Step 7:''' Depending on the automation of your software, maybe start and finish for all some or all tasks are filled out, if not fill out the remaining.

'''Step 8:''' Add additional features you need like responsibility, resources, critical path, milestones, progress etc.

'''Step 9:''' Update the Gantt Chart during the execution of the project

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure. The Work Breakdown Structure is a tool that can be used to specify the project scope and divide it into smaller manageable tasks. After deciding on the tasks and scope the Gantt Chart can be used for planning, visualization, and control<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects but there is a risk of the Gantt Chart getting overly complicated, if all minor tasks are added when they arise, it can confuse the users and be a disadvantage for the project manager. If the chart is unnecessarily complicated and a change happens in the project, there is a risk of the chart eventually ending outdated if the manager does not have the necessary time e.g., if they are busy managing the occurred problems. <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software<ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-26T10:30:01Z

S175068: /* Guideline on how to get started using Gantt Charts */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=
[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependency, critical path, responsibility, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. It also gives a guideline on how to get started using Gantt Charts as well as discussing the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used but in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependency, critical path, responsibility, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added fetures<ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref><ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref><ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref> During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user. <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company. <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|200px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref> Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

[[File:Gantt Chart microsoft project dependency.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

There are generally four ways of describing dependency<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, if task 5 are dependent on task 4:
#Finish to start (FS), task 5 cannot start until task 4 is finished.
#Start to start (SS), task 5 cannot start until task 4 is started.
#Start to finish (SF), task 5 cannot be finished until task 4 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.

A variation of these is that there can be added a lead time or lag time one these dependencies. This will normally be done by e.g., FS+2days, this means that task 5 cannot start until 2 days later than task 4 is finished. An example is a wall that was cast and needs to dry for two days before it can be painted. The task ‘painting’ will have a lag time of 2 days on the finish to start dependency on ‘casting’. Dependency visualized in Microsoft project can be seen in figure 5.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===

[[File:Gantt Chart microsoft project progress.png|thumb|250px|Figure 6: Progress in Microsoft Project, own creation]]

The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress. In figure 6 the progress can be seen as it is visualized in Microsoft Project, the middle of the bars change color. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget. <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support deapartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Guideline on how to get started using Gantt Charts =
'''Step 1:''' Decide on the level of detail.

'''Step 2:''' Decide on which tasks to include.

'''Step 3:''' Write the tasks in descending order in the column leftmost, from starting first to last.

'''Step 4:''' Select a start date.

'''Step 5:''' Ad duration for your tasks

'''Step 6:''' Add predecessors.

'''Step 7:''' Depending on the automation of your software, maybe start and finish for all some or all tasks are filled out, if not fill out the remaining.

'''Step 8:''' Add additional features you need like responsibility, resources, critical path, milestones, progress etc.

'''Step 9:''' Update the Gantt Chart during the execution of the project

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure that can divide the project into tasks<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects but there is a risk of the Gantt Chart getting overly complicated, if all minor tasks are added when they arise, it can confuse the users and be a disadvantage for the project manager. If the chart is unnecessarily complicated and a change happens in the project, there is a risk of the chart eventually ending outdated if the manager does not have the necessary time e.g., if they are busy managing the occurred problems. <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software<ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-26T10:29:40Z

S175068: /* Level of detail */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=
[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependency, critical path, responsibility, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. It also gives a guideline on how to get started using Gantt Charts as well as discussing the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used but in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependency, critical path, responsibility, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added fetures<ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref><ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref><ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref> During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user. <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company. <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|200px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref> Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

[[File:Gantt Chart microsoft project dependency.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

There are generally four ways of describing dependency<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, if task 5 are dependent on task 4:
#Finish to start (FS), task 5 cannot start until task 4 is finished.
#Start to start (SS), task 5 cannot start until task 4 is started.
#Start to finish (SF), task 5 cannot be finished until task 4 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.

A variation of these is that there can be added a lead time or lag time one these dependencies. This will normally be done by e.g., FS+2days, this means that task 5 cannot start until 2 days later than task 4 is finished. An example is a wall that was cast and needs to dry for two days before it can be painted. The task ‘painting’ will have a lag time of 2 days on the finish to start dependency on ‘casting’. Dependency visualized in Microsoft project can be seen in figure 5.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===

[[File:Gantt Chart microsoft project progress.png|thumb|250px|Figure 6: Progress in Microsoft Project, own creation]]

The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress. In figure 6 the progress can be seen as it is visualized in Microsoft Project, the middle of the bars change color. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget. <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support deapartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt Chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Guideline on how to get started using Gantt Charts =
'''Step 1:''' Decide on the level of detail.

'''Step 2:''' Decide on which tasks to include.

'''Step 3:''' Write the tasks in descending order in the column leftmost, from starting first to last.

'''Step 4:''' Select a start date.

'''Step 5:''' Ad duration for your tasks

'''Step 6:''' Add predecessors.

'''Step 7:''' Depending on the automation of your software, maybe start and finish for all some or all tasks are filled out, if not fill out the remaining.

'''Step 8:''' Add additional features you need like responsibility, resources, critical path, milestones, progress etc.

'''Step 9:''' Update the Gantt Chart along with the project

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure that can divide the project into tasks<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects but there is a risk of the Gantt Chart getting overly complicated, if all minor tasks are added when they arise, it can confuse the users and be a disadvantage for the project manager. If the chart is unnecessarily complicated and a change happens in the project, there is a risk of the chart eventually ending outdated if the manager does not have the necessary time e.g., if they are busy managing the occurred problems. <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software<ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-26T10:29:03Z

S175068: /* Responsibility and resources */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=
[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependency, critical path, responsibility, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. It also gives a guideline on how to get started using Gantt Charts as well as discussing the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used but in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependency, critical path, responsibility, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added fetures<ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref><ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref><ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref> During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user. <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company. <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|200px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref> Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

[[File:Gantt Chart microsoft project dependency.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

There are generally four ways of describing dependency<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, if task 5 are dependent on task 4:
#Finish to start (FS), task 5 cannot start until task 4 is finished.
#Start to start (SS), task 5 cannot start until task 4 is started.
#Start to finish (SF), task 5 cannot be finished until task 4 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.

A variation of these is that there can be added a lead time or lag time one these dependencies. This will normally be done by e.g., FS+2days, this means that task 5 cannot start until 2 days later than task 4 is finished. An example is a wall that was cast and needs to dry for two days before it can be painted. The task ‘painting’ will have a lag time of 2 days on the finish to start dependency on ‘casting’. Dependency visualized in Microsoft project can be seen in figure 5.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===

[[File:Gantt Chart microsoft project progress.png|thumb|250px|Figure 6: Progress in Microsoft Project, own creation]]

The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress. In figure 6 the progress can be seen as it is visualized in Microsoft Project, the middle of the bars change color. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget. <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occur.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support deapartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Guideline on how to get started using Gantt Charts =
'''Step 1:''' Decide on the level of detail.

'''Step 2:''' Decide on which tasks to include.

'''Step 3:''' Write the tasks in descending order in the column leftmost, from starting first to last.

'''Step 4:''' Select a start date.

'''Step 5:''' Ad duration for your tasks

'''Step 6:''' Add predecessors.

'''Step 7:''' Depending on the automation of your software, maybe start and finish for all some or all tasks are filled out, if not fill out the remaining.

'''Step 8:''' Add additional features you need like responsibility, resources, critical path, milestones, progress etc.

'''Step 9:''' Update the Gantt Chart along with the project

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure that can divide the project into tasks<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects but there is a risk of the Gantt Chart getting overly complicated, if all minor tasks are added when they arise, it can confuse the users and be a disadvantage for the project manager. If the chart is unnecessarily complicated and a change happens in the project, there is a risk of the chart eventually ending outdated if the manager does not have the necessary time e.g., if they are busy managing the occurred problems. <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software<ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-26T10:28:46Z

S175068: /* Responsibility and resources */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=
[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependency, critical path, responsibility, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. It also gives a guideline on how to get started using Gantt Charts as well as discussing the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used but in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependency, critical path, responsibility, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added fetures<ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref><ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref><ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref> During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user. <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company. <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|200px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref> Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

[[File:Gantt Chart microsoft project dependency.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

There are generally four ways of describing dependency<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, if task 5 are dependent on task 4:
#Finish to start (FS), task 5 cannot start until task 4 is finished.
#Start to start (SS), task 5 cannot start until task 4 is started.
#Start to finish (SF), task 5 cannot be finished until task 4 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.

A variation of these is that there can be added a lead time or lag time one these dependencies. This will normally be done by e.g., FS+2days, this means that task 5 cannot start until 2 days later than task 4 is finished. An example is a wall that was cast and needs to dry for two days before it can be painted. The task ‘painting’ will have a lag time of 2 days on the finish to start dependency on ‘casting’. Dependency visualized in Microsoft project can be seen in figure 5.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===

[[File:Gantt Chart microsoft project progress.png|thumb|250px|Figure 6: Progress in Microsoft Project, own creation]]

The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress. In figure 6 the progress can be seen as it is visualized in Microsoft Project, the middle of the bars change color. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget. <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know which team member the manager should go to if a task e.g., is behind schedule. The responsibility can also show if it is always the same team member who is ahead or behind on the responsibilities, and the project manager can then be proactive trying to solve problems before they occurs.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support apartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Guideline on how to get started using Gantt Charts =
'''Step 1:''' Decide on the level of detail.

'''Step 2:''' Decide on which tasks to include.

'''Step 3:''' Write the tasks in descending order in the column leftmost, from starting first to last.

'''Step 4:''' Select a start date.

'''Step 5:''' Ad duration for your tasks

'''Step 6:''' Add predecessors.

'''Step 7:''' Depending on the automation of your software, maybe start and finish for all some or all tasks are filled out, if not fill out the remaining.

'''Step 8:''' Add additional features you need like responsibility, resources, critical path, milestones, progress etc.

'''Step 9:''' Update the Gantt Chart along with the project

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure that can divide the project into tasks<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects but there is a risk of the Gantt Chart getting overly complicated, if all minor tasks are added when they arise, it can confuse the users and be a disadvantage for the project manager. If the chart is unnecessarily complicated and a change happens in the project, there is a risk of the chart eventually ending outdated if the manager does not have the necessary time e.g., if they are busy managing the occurred problems. <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software<ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
<references/>

Gantt Charts

2021-02-26T10:22:12Z

S175068: /* Critical path */

A page describing Gantt Charts as a tool in Project Management.

=Abstract=
[[File:Gantt_Chart_Excel.png|500px|thumb|Figure 1: Simple Gantt Chart made in Microsoft Excel, own creation]]

Gantt Charts are a very useful tool in Project Management. It is one of the most widely used tools in the field of project managers. A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. The bars represent the different tasks on a timeline. The bar length is relative to the needed time to complete the task. This makes it a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used to structure and control a project both in the planning phase and the execution phase. Gantt Charts can be either very simple or contain more complex information, as milestones, dependency, critical path, responsibility, and resources, or be somewhere in between.

This article first describes Gantt Charts' relation to Project Management, then it gives a historical view on Gantt Charts. Furthermore, it describes the tool and the different features that can be included. It also gives a guideline on how to get started using Gantt Charts as well as discussing the limitations of using Gantt Charts. In the end, it gives an overview of some software to use when making Gantt Charts.

=Gantt Chart in Project Management=

A Gantt Chart is a bar chart showing the different tasks necessary to complete a project. A simple Gantt Chart can be seen in figure 1. The green bars represent the tasks furthest to the left, visualized on the timeline. The timescale can be seen at the top, and the bar length will be relative to the time needed to complete the specific task. A Gantt Chart is a good tool for visualization and gives an easy overview of a project. A Gantt Chart can be used but in the planning and the execution phase of a project and it can be used to structure and control the project. Gantt Charts can be either very simple or contain more complex information, as milestones, dependency, critical path, responsibility, and resources, these features will be described later in the article in the section 'Features of the Gantt Chart'.

There are many purposes of a Gantt Chart some of which are:

* Visualization of a project on a timeline

* Presenting project progress

* Helping with time and money-saving

* Ease project planning and resource scheduling

* Tracking labor hours

* Status reporting

Together these make the Gantt Chart a great project managing tool, that can be used for many different types of projects as the user themselves can decide which features to include thus how complex it should be. The purpose of the Gantt Chart can variate from project to project depending on the added fetures<ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96. </ref><ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49-53. </ref><ref> Ramachandran, K. K., and K. K. Karthick. “Gantt Chart: An Important Tool of Management.” International Journal of Innovative Technology and Exploring Engineering, vol. 8, no. 7, 2019, pp. 140–42.</ref>.

The Gantt Chart as a tool and the purpose of it, fits very well with the PRINCE2 standard. “Plans provide the backbone of the management required for any project; without a plan, there can be no control” <ref name=BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, page 94 and 113. </ref>. As the PRINCE2 standard states, it is important to start out with a plan, not only to execute the project but also to control the project. A written plan makes it possible to trace, the progress or lack thereof and monitor the project. Gantt Charts are one of the most commonly used tools for project managers when managing projects <ref>White, Diana, and Joyce Fortune. “Current Practice in Project Management — an Empirical Study.” International Journal of Project Management, vol. 20, no. 1, 2002, pp. 1–11. ScienceDirect, doi:10.1016/s0263-7863(00)00029-6.</ref> . As written above Gantt Charts can be used for visualization and control of a plan, and it can e.g., help track and visualize progress, which can make it easier to control the project.

=Historical State of the Art =

Back in 1896, Karol Adamiecki invented a visual chart showing operations in a production. The chart showed the sequence of the activities and the process-time. The final improved form of the Hamonogram, as this chart was called was published in an article in 1931 in ‘Przeglad Organizacji (Organizational Review)’ <ref> Marsh, E. R. “Research Notes. THE HARMONOGRAM OF KAROL ADAMIECKI.” Academy of Management Journal, vol. 18, no. 2, 1975, pp. 358–64. EBSCO, doi:10.2307/255537. </ref>.

In 1903 Henry L. Gantt first described his version of the Gantt Chart in the article ‘A graphical daily balance in manufacture’. The chart was used as a production planning tool and it linked the different components to secure, they were ready when needed in the later assembly. The chart furthermore showed the required work against the actual work, showing any inconsistency. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref> During the years, the tool was improved, in the book ‘The Gantt Chart’ by W. Clark from 1925 it is stated that the Gantt Chart should cover processes in the entire factory to make one coherent plan, it should also consider all orders in the scheduling, and that the scheduling should be accurate to decrease inventory. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

In the 1960s production management texts like Moore’s ‘Manufacturing Management’ from 1965 and Buffa’s ‘Modern Production Management’ from 1969 start to address the use of Gantt Charts for projects. As the use of computers increased during the 1990s the Gantt Chart had its improvements like the implementation of features visualizing, critical path, slack, progress, completion, past due, and many others. <ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5. </ref>.

Since then, the Gantt Chart has kept evolving together with the technology. Nowadays there is plenty of different software both offline and online made to generate Gantt Charts, some of these software are well integrated with our other day-to-day working tools, e.g., Project for the Webs integration in Microsoft Teams <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref>. Some examples of the use of Gantt charts in recent years are the following.

A study from 2016 shows the use of Gantt Charts as a tool for analyzing behavior patterns, here the Gantt Chart is used to visualizing the movement of specific people and the activities they do, the visualization helps understand gatherings and small meetups. The conference paper furthermore states that empty time intervals can be folded so they do not confuse the user. <ref> Gupta, Shrey, et al. MovementSlicer: Better Gantt Charts for Visualizing Behaviors and Meetings in Movement Data. IEEE Pacific Visualization Symposium, 2016, page 168.</ref>

A study from 2019 describes the use of implementing Gantt Charts in open-source ERP-systems, this makes it possible to automatically generate visual charts over production schedules. The research paper states that the feature can help improve production planning in a company. <ref> Nafianto, Chandratya, et al. Development of Flexible Production Scheduling by Applying Gantt Charts In Manufacturing Module Open Source ERP (Case Study CV. XYZ). N/A, 2019. </ref>.

In the book 'The Gantt Chart' from 1922 it is stated that the Gantt Chart can be applied to any human activity, this is what is seen more and more today, as the use of Gantt Charts expands together with the technology<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922.</ref>.

=Features of the Gantt Chart=
A Gantt Chart consist of a number of rows and columns with information, and a bar visualization of the information shown on a timeline. Depending on the use of the Gantt Chart the time will usually be shown as days or weeks, but it could even be made in hours or minutes if a very detailed plan should be made for a project. The rows show the different tasks that need to be completed within the project.
Depending on which program the user decides to make their Gantt Chart in, there are different features to add. The following will describe some of the most common features there can be included in a Gantt Chart view.

[[File:Gantt Chart microsoft project.png|1000px|thumb|centre|Figure 2: Gantt Chart in Microsoft Project, own creation]]

===Tasks, duration, start and finish===
Task description and start time for the task are the main elements of the Gantt Chart together with either duration or finish time of the task and they should be included to make a proper Gantt Chart. The first column in a Gantt Chart will usually show the tasks. In most software, it will be possible to make subtasks so multiple tasks are included in the main tasks, tasks and subtasks can be seen in red in figure 3.

[[File:Gantt Chart microsoft project task etc.png|thumb|centre|800px|Figure 3: Task, duration, start and finish in Microsoft Project, own creation]]

An example on why subtask are useful could be if you are building a house. Here you first need to make the foundation, then build the walls and roof at last you can decorate the inside. Under foundation there could be multiple subtasks like removing soil, adding gravel, leveling out, and casting the foundation. To show that this is all connected the sub-task function is practical. Often is it also possible to change view so you do not see the sub-tasks, but just the main tasks, this makes it possible to have a detailed plan but also get a higher-level overview.
Then there will be a column for the duration of the specific task, marked with orange in figure 3. Dependent on the settings this can be in different time intervals, it will usually be in hours or days. Then there will be a start time and a view of the finish time for the task, these are marked with green and blue in figure 3.

===Milestones===
[[File:Gantt Chart microsoft project milestone.png|thumb|200px|Figure 4: Milestones in Microsoft Project, own creation]]
In most Gantt Charts it is also possible to add milestones. This will usually be shown as a diamond shape, and in e.g., Microsoft Project they are made by setting the duration for a task to zero days, this can be seen in figure 4. Milestones symbolize a change or a stage in the project and they can help the project manager control that the project is on track and secure the stakeholders about the progress in the project. Milestones are important as they show the completion of a key activity, it can also early indicate problems in the project. The number of milestones is important as too few milestones make it difficult to keep track of the progress and too many make the milestones lose their value <ref name= BS> AXELOS. Managing Successful Projects with PRINCE2 2017 Edition, The Stationery Office Ltd, 2017. ProQuest Ebook Central, https://ebookcentral-proquest- com.proxy.findit.dtu.dk/lib/DTUDK/detail.action?docID=4863041, page 94 and 113. </ref> Besides this, milestones are a great place to mark this completion of part of the project with a celebration to keep up the good spirit and show appreciation of the team members.

===Dependency===
In most Gantt Chart software dependency between the different tasks can be added. Dependency is an important feature in a Gantt Chart as it visualizes how a delay in a single task affects the entire duration of the project.

[[File:Gantt Chart microsoft project dependency.png|thumb|centre|800px|Figure 5: Dependencies in Microsoft Project, own creation]]

There are generally four ways of describing dependency<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>. Below is an example of the four dependencies, if task 5 are dependent on task 4:
#Finish to start (FS), task 5 cannot start until task 4 is finished.
#Start to start (SS), task 5 cannot start until task 4 is started.
#Start to finish (SF), task 5 cannot be finished until task 4 is started.
#Finish to finish (FF), task 5 cannot be finished until task 4 is finished.

A variation of these is that there can be added a lead time or lag time one these dependencies. This will normally be done by e.g., FS+2days, this means that task 5 cannot start until 2 days later than task 4 is finished. An example is a wall that was cast and needs to dry for two days before it can be painted. The task ‘painting’ will have a lag time of 2 days on the finish to start dependency on ‘casting’. Dependency visualized in Microsoft project can be seen in figure 5.

===Critical path===
The critical path is the sequence of tasks that determines the duration of the project as well as the minimum time required to complete the entire project. If your final deadline is further away than the required time for your critical path the extra time is referred to as slack time. The slack time is the time the project can be delayed without exceeding the deadline <ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>. In the Gantt Chart software, the critical path can sometimes be made automatically in e.g., Projects for the Web and Microsoft Project it happens by clicking a box stating that you want to show the critical path. After stating this the critical path changes color to visualize the path, this can be seen as the salmon-colored tasks in figure 2. The critical path is only shown on tasks that are not yet completed, hence only three tasks are marked as critical in figure 2 since the earlier tasks are already completed. The visualization of the critical path is a great tool in Gantt Charts because it shows which tasks there needs to be extra focus on to keep the plan and stay within the deadlines. Tasks that are not on the critical path will have some slack time, and if a prioritization should be made, it will usually make sense to focus on the tasks on the critical path. If the timeframe for different tasks changes during the project, the critical path might also change.

===Progress===

[[File:Gantt Chart microsoft project progress.png|thumb|250px|Figure 6: Progress in Microsoft Project, own creation]]

The tracking of progress in Gantt Charts is another useful feature. In most software the progress for each task can be typed in as a percentage completion of the task, the completed part of the task will then change color to visualize the progress. In figure 6 the progress can be seen as it is visualized in Microsoft Project, the middle of the bars change color. This feature is very useful for the project manager in the execution of a project. As he visually can see how far along a task is and if some tasks are ahead of behind schedule. This makes it possible for the project manager to keep track of the actual progress compared to the planned progress and act on any delay issues and potentially make changes to keep the project on schedule and on budget. <ref name=painless> McGhee, Pamela, and Peter McAliney. Painless Project Management: A Step-by-Step Guide for Planning, Executing, and Managing Projects. 1st ed., e-book, Wiley, 2007, page 96-101. </ref>

===Responsibility and resources===
In some software, it is possible to show the responsible person for a task. This makes it possible for the project manager to always know who he or she should go to if a task e.g., is behind schedule. The project manager can also get an overview on if a certain manager is always behind on the responsibilities, and the project manager can then be proactive trying to solve the delays before they happen.

Sometimes it is possible to add resources to the different tasks as well. This is especially beneficial if some of the tasks need the same resources and there is a need for effective resource planning<ref>Jaber, Khaled, et al. “An Empirical Study on the Effect of 3D Visualization for Project Tasks and Resources.” Journal of Systems and Software, vol. 115, 2016, pp. 1–17. ScienceDirect, doi:10.1016/j.jss.2016.01.011.</ref>. A case where this would be beneficial could be the development of a new app. Some tasks might require assistance from a specific technical support apartment. If these tasks are planned at the same time, the support apartment might not have the resources to help on multiple tasks, here it would be important to make the plan according to the available resources.

===Level of detail===
A Gantt chart can be made on various levels with different degree of detail.
A '''Top-level Gantt Chart''' is a Gantt Chart showing the main project phases. This gives the project manager a good overview of the entire project and an outline of the time frame. It does not specify the different phases or subprojects, meaning it will not describe the specific tasks. The Top-level Gantt Chart is a tool well used towards the sponsors, executives, and external partners who only need to see the big picture for the project. It can also be used to keep subprojects within the timeframe by clearly marking critical deadlines and dependent subprojects. <ref name=Vargas> Vargas, Ricardo Viana. Practical Guide to Project Planning (ESI International Project Management Series). PAP/CDR, e-book, Auerbach Publications, 2008, page 49. </ref>.

A more detailed Gantt Chart showing the different individual tasks can be used to structure a project on a more operational level. This type of Gantt Chart is useful for the employees directly involved in the project e.g., the workers performing or managing tasks that have other tasks depending on them. This is also a useful tool for the project manager to visually show the workers the progress and the critical tasks that might be in the project<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>. One way of doing this could be by weekly going through the chart with the workers e.g., on a board meeting, and making sure it is always visual to keep the workers aware of deadlines, etc. It is important to update the chart, so it presents the actual state.

= Guideline on how to get started using Gantt Charts =
'''Step 1:''' Decide on the level of detail.

'''Step 2:''' Decide on which tasks to include.

'''Step 3:''' Write the tasks in descending order in the column leftmost, from starting first to last.

'''Step 4:''' Select a start date.

'''Step 5:''' Ad duration for your tasks

'''Step 6:''' Add predecessors.

'''Step 7:''' Depending on the automation of your software, maybe start and finish for all some or all tasks are filled out, if not fill out the remaining.

'''Step 8:''' Add additional features you need like responsibility, resources, critical path, milestones, progress etc.

'''Step 9:''' Update the Gantt Chart along with the project

= Limitations of the Gantt Chart =

First of all, Gantt Charts are limited according to the plan already made. Gantt Charts are not a designated planning tool, but they should be used in combination with other tools like Work Breakdown Structure that can divide the project into tasks<ref>Cicala, Gus. “Developing a Work Breakdown Structure.” The Project Managers Guide to Microsoft Project 2019, 1st ed., Apress, 2020, pp. 123–25.</ref>.

Gantt Charts are great for small projects but there is a risk of the Gantt Chart getting overly complicated, if all minor tasks are added when they arise, it can confuse the users and be a disadvantage for the project manager. If the chart is unnecessarily complicated and a change happens in the project, there is a risk of the chart eventually ending outdated if the manager does not have the necessary time e.g., if they are busy managing the occurred problems. <ref> Ellis, George. “Chapter 19 - Workflow—Visual Management for Initiatives and Projects.” The Next Generation of Continuous Improvement for Knowledge Work, 1st ed., Butterworth-Heinemann, 2020, pp. 345–66. </ref> Therefore there are some limitations for the project size when using Gantt Charts, but these limitations will also depend on the project manager's experience with using Gantt Charts, if the manager has used it a lot he will be able to manage bigger projects than an inexperienced manager.

The different software has limitations as well e.g., Microsoft Excel is not suitable for as big projects at Microsoft Project, before making a Gantt Chart it will therefore be beneficial to look at the extend of the project to find a suitable software<ref>Lee, Sangkon, and Olga A. Shvetsova. “Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry.” Processes, vol. 7, no. 12, 2019, p. 8, doi:10.3390/pr7120917.</ref>.

= Useful programs to produce Gantt Charts=
'''Excel:'''
Excel is a very simple software there can be used to make simple Gantt Charts for projects. It is relatively easy to make your own simple Gantt Charts by manually or automatically formatting cells depending on when the task is located. Excel has various templates that can be used for making Gantt Charts more automated. Most of these will only include the features task, start, finish, duration, and sometimes progress. Some examples are these Simple Gantt Chart [https://templates.office.com/en-us/simple-gantt-chart-tm16400962], Date tracking Gantt chart [https://templates.office.com/en-us/date-tracking-gantt-chart-tm22588720], and Agile Gantt chart [https://templates.office.com/en-us/agile-gantt-chart-tm55723235]. Excel is a good starting point if you have a simple project without too many dependencies and few tasks.

This reference is a step-by-step guideline on how to create a simple Gantt Chart in Microsoft Excel or PowerPoint from excel data <ref> “Excel Gantt Chart Tutorial +Free Template + Export to PPT.” Office Timeline, www.officetimeline.com/make-gantt-chart/excel. Accessed 18 Feb. 2021. </ref>

'''Microsoft Project:'''
Microsoft Project is another well-known project management software. Microsoft Project has a lot of different features including automatic scheduling, resource and material planning, cost tracking, automatic progress reports, and portfolio management since a user can connect multiple projects and use the same resources. As Microsoft Project has many features it can seem quite complicated and confusing when first starting using it. <ref> Santos, Jose Maria Delos. “Microsoft Project Pros & Cons.” Project-Management.Com, 12 Feb. 2021, project-management.com/the-pros-and-cons-of-using-microsoft-project-software. </ref>

'''Project for the Web:'''
Project for the Web is Microsoft’s newest solution for cloud-based project management. Project for the Web is an easy to use very intuitive software there are well integrated with Microsoft Teams and in general on the Microsoft platform. Project for the Web can be used to plan and manage projects of any size. <ref name=PFTW> Microsoft. “What Is Project for the Web?” Microsoft, support.microsoft.com/en-us/office/what-is-project-for-the-web-c19b2421-3c9d-4037-97c6-f66b6e1d2eb5. Accessed 19 Feb. 2021. </ref> Project for the Web currently have three main views a grid view, showing the tasks and associated information, board view, showing the tasks as small notes divided into the user's desired categories, and a timeline view, showing the actual Gantt Chart. Project for the Web has less features than Microsoft Project, but the easy access and possibilities of multiple people editing and working on the same project at the same time make it ideal for collaboration and working as a team from different locations.

'''Other online software:'''
There is a lot of other online Gantt Chart software. Some of which are, TeamGantt.com [https://www.teamgantt.com/h], ProejectManager.com, [https://www.projectmanager.com/] and Monday.com [https://monday.com/]

=Annotated Bibliography=

The book ''''The Gantt Chart'''' from 1922 by Wallace Clark describes the original use of Gantt Charts and the purpose. It is recommended to read this book if you are interested in how Gantt himself used the tool.<ref name=theGanttChart> Clark, Wallace. The Gantt Chart, a Working Tool of Management. The Ronald Press Company, 1922</ref>.

The Journal article and Conference paper ''''Gantt Charts: A Centenary Appreciation'''' by James M. Wilson describes the development of the Gantt Chart and the first application of Gantt Charts for projects<ref name="GanttChartCentenaryAppreciation"> Wilson, James M. “Gantt Charts: A Centenary Appreciation.” European Journal of Operational Research, vol. 149, no. 2, 2003, pp. 430-435. ScienceDirect, doi:10.1016/s0377-2217(02)00769-5.</ref>.

The Journal article ''''Effective Use of Gantt Chart for Managing Large Scale Projects'''' by Pankaja Pradeep Kumar gives an introduction on how to plan and control large-scale projects, the main focus is on the construction industry<ref name=EffecUse> Kumar, Pankaja Pradeep. “Effective Use of Gantt Chart for Managing Large Scale Projects.” Cost Engineering Journal, 2005, p. 15. EBSCO. </ref>.

The book ''''Project Management: A Systems Approach to Planning, Scheduling, and Controlling'''' by Harold Kerzner gives an end-to-end description of project management including the use of Gantt Charts<ref name=PMsys> Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. 10th ed., e-book, Wiley, 2009, page 495-502. </ref>.

= References =
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