PERT - Revision history

Tkokotas at 18:26, 17 November 2018

2018-11-17T18:26:42Z

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			''Developed by Ignacio López Cabañas''


	=Abstract=		=Abstract=

S161357: /* Event-driven */

2017-09-26T16:33:43Z

Event-driven

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	\|[[File:diagramPERT7.PNG \|200px\|thumb\|Fig. 7. Example of events with the same predecessor when calculating its final point in the PERT diagram]]		\|[[File:diagramPERT7.PNG \|200px\|thumb\|Fig. 7. Example of events with the same predecessor when calculating its final point in the PERT diagram]]
	\|}		\|}


	[[File:diagramPERT8.PNG \|400px\|thumb\|center\|Fig.8. Example of complete PERT diagram]]		[[File:diagramPERT8.PNG \|400px\|thumb\|center\|Fig.8. Example of complete PERT diagram]]

S161357: /* Event-driven */

2017-09-26T16:27:12Z

Event-driven

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	\|[[File:diagramPERT7.PNG \|200px\|thumb\|Fig. 7. Example of events with the same predecessor when calculating its final point in the PERT diagram]]		\|[[File:diagramPERT7.PNG \|200px\|thumb\|Fig. 7. Example of events with the same predecessor when calculating its final point in the PERT diagram]]
	\|}		\|}
			[[File:diagramPERT8.PNG \|400px\|thumb\|center\|Fig.8. Example of complete PERT diagram]]

	==Activity-driven==		==Activity-driven==

S161357: /* Time concepts */

2017-09-26T08:33:35Z

Time concepts

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	{\|style="margin: 0 auto;"		{\|style="margin: 0 auto;"
	\|[[File:formula1_PERT.PNG \|200px\|frame\|right]]		\|[[File:formula1_PERT.PNG \|200px\|frame\|right\| Expected time]]
	\|[[File:formula2_PERT.PNG \|200px\|frame\|right]]		\|[[File:formula2_PERT.PNG \|200px\|frame\|right\| Standard deviation]]
	\|}		\|}

S161357: /* Event-driven */

2017-09-26T08:29:56Z

Event-driven

S161357: /* Abstract */

2017-09-26T08:22:43Z

Abstract

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	=Abstract=		=Abstract=

	The program (or project) evaluation and review or PERT is a statistical tool designed to analyze and represent the tasks involved in completing a given project. It is used in project management and commonly together with the critical path method or CPM to control, plan and schedule.		The program (or project) evaluation and review or PERT is a statistical tool designed to analyze and represent the tasks involved in completing a given project. It is used in project management and commonly together with the critical path method (CPM) to control, plan and schedule.

	This project management method is used for analyzing all the tasks involved in completing a project focusing on dealing with completion time rather than the costs of the project. It incorporates details about all the task such as their duration and required finished activities, also managing the uncertainty of the complete duration of each task.		This project management method is used for analyzing all the tasks involved in completing a project focusing on dealing with completion time rather than the costs of the project. It incorporates details about all the task such as their duration and required finished activities, also managing the uncertainty of the complete duration of each task.

S161357: /* References */

2017-09-26T08:16:14Z

References

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	The major advantages and disadvantages and how to palliate them are explained in the following article.		The major advantages and disadvantages and how to palliate them are explained in the following article.

	*11. OBS Business School (20/09/2017), "Principales usos y beneficios del ~~diagram~~ PERT", http://www.obs-edu.com/int/blog-project-management/planificacion-de-las-actividades-y-tiempo-de-un-proyecto/principales-usos-y-beneficios-del-diagrama-de-pert		*11. OBS Business School (20/09/2017), "Principales usos y beneficios del diagrama PERT", http://www.obs-edu.com/int/blog-project-management/planificacion-de-las-actividades-y-tiempo-de-un-proyecto/principales-usos-y-beneficios-del-diagrama-de-pert

S161357: /* References */

2017-09-21T09:25:12Z

References

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	*10. Intervention (India) PVT.Ltd. (18/09/2017), "PERT/CPM for Project Scheduling & Management", http://www.interventions.org/pertcpm/		*10. Intervention (India) PVT.Ltd. (18/09/2017), "PERT/CPM for Project Scheduling & Management", http://www.interventions.org/pertcpm/

			The major advantages and disadvantages and how to palliate them are explained in the following article.

			*11. OBS Business School (20/09/2017), "Principales usos y beneficios del diagram PERT", http://www.obs-edu.com/int/blog-project-management/planificacion-de-las-actividades-y-tiempo-de-un-proyecto/principales-usos-y-beneficios-del-diagrama-de-pert

S161357: /* Assumptions and palliation of disadvantages. */

2017-09-21T09:21:38Z

Assumptions and palliation of disadvantages.

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	*Using other techniques such as Gantt diagram, as mentioned before, to complement the PERT diagram can be helpful to have a better overview of the project.		*Using other techniques such as Gantt diagram, as mentioned before, to complement the PERT diagram can be helpful to have a better overview of the project.

	*Automatization of processes. Nowadays technology is one of the most powerful ~~tool~~ for managers. Using specialized software for drawing the PERT diagram and doing online updates can minimize errors related ~~with~~ the information flow within the people involved in the project.		*Automatization of processes. Nowadays technology is one of the most powerful tools for managers. Using specialized software for drawing the PERT diagram and doing online updates can minimize errors related to the information flow within the people involved in the project.[11]

	=References=		=References=

S161357: /* Disadvantages */

2017-09-21T09:21:20Z

Disadvantages

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	*Critical path: the PERT diagram is based on probabilities and the critical path is found using them, therefore any change or error of the activities involved in the critical path might change it and reveal the project has been focusing on the wrong activities.		*Critical path: the PERT diagram is based on probabilities and the critical path is found using them, therefore any change or error of the activities involved in the critical path might change it and reveal the project has been focusing on the wrong activities.

	*Loss of efficiency: if the dependencies of the activities are changed, that will conduct to a less efficient project.		*Loss of efficiency: if the dependencies of the activities are changed, that will conduct to a less efficient project.[11]

	=Assumptions and palliation of disadvantages.=		=Assumptions and palliation of disadvantages.=

← Older revision		Revision as of 08:29, 26 September 2017
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	==Event-driven==		==Event-driven==
	[[File:tablaPERT1.PNG \|200px\|thumb\|right\| Example of a list of activities]]		[[File:tablaPERT1.PNG \|200px\|thumb\|right\|Fig. 1. Example of a list of activities]]

	[[File:diagramPERT3.PNG \|200px\|thumb\|right\| Example of event represented in the PERT diagram]]		[[File:diagramPERT3.PNG \|200px\|thumb\|right\| Fig. 2. Example of event represented in the PERT diagram]]

	[[File:diagramPERT2.PNG \|200px\|thumb\|right\| Example of two consecutive events represented in the PERT diagram when calculating the starting]]		[[File:diagramPERT2.PNG \|200px\|thumb\|right\| Fig. 3. Example of two consecutive events represented in the PERT diagram when calculating the starting]]

	Prior to starting drawing the PERT diagram, there are some rules that have to be followed to draw it correctly:		Prior to starting drawing the PERT diagram, there are some rules that have to be followed to draw it correctly:
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	*Activities with zero duration can be added in order to not break any rule, usually written as “f(0)”.		*Activities with zero duration can be added in order to not break any rule, usually written as “f(0)”.

	The first step is to make a list of all the activities including predecessor activities and expected time. This provides an overview of all the tasks involved in the project.		The first step is to make a list of all the activities including predecessor activities and expected time (Fig.1). This provides an overview of all the tasks involved in the project.

	Secondly, a Gantt diagram can be drawn in order to have a more visual representation of the activities and their dependencies.		Secondly, a Gantt diagram can be drawn in order to have a more visual representation of the activities and their dependencies.

	In this PERT diagram, the events are represented by a circle with its number, the activities are drawn as arrows linking the different events.		In this PERT diagram, the events are represented by a circle with its number, the activities are drawn as arrows linking the different events (Fig.2).
	Inside the circles, the starting and end point, are written. Starting from the initial event, with starting point 0, the rest of starting points of the rest of events is obtained by the sum of the longest path of predecessor activities.		Inside the circles, the starting and end point, are written. Starting from the initial event, with starting point 0, the rest of starting points of the rest of events is obtained by the sum of the longest path of predecessor activities (Fig.3 and Fig.4).

	{\|style="margin: 0 auto;"		{\|style="margin: 0 auto;"
	\|[[File:diagramPERT5.PNG \|200px\|thumb\| Example of a event with more than one predecessor event when calculating its ~~stating~~ point in the PERT diagram]]		\|[[File:diagramPERT5.PNG \|200px\|thumb\| Fig. 4. Example of an event with more than one predecessor event when calculating its starting point in the PERT diagram]]
	\|[[File:diagramPERT4.PNG \|200px\|thumb\| Example of the final event represented in the PERT diagram]]		\|[[File:diagramPERT4.PNG \|200px\|thumb\| Fig. 5. Example of the final event represented in the PERT diagram]]
	\|}		\|}

	Once the final event is reached, it has to be taken into account that the initial and the final point are the same, meaning the end of the project. In order to note the final point of the previous events, the inverse procedure is done.		Once the final event is reached, it has to be taken into account that the initial and the final point are the same, meaning the end of the project. In order to note the final point of the previous events, the inverse procedure is done (Fig.5).

	The final point is determined by removing the duration of the successor activities starting from the final event. The slack can be calculated from the duration of the critical path by making the difference between the non-critical and the critical one. By definition, the initial and final activity, have zero slack.		The final point is determined by removing the duration of the successor activities starting from the final event. The slack can be calculated from the duration of the critical path by making the difference between the non-critical and the critical one (Fig. 6 and Fig.7). By definition, the initial and final activity, have zero slack.

	{\|style="margin: 0 auto;"		{\|style="margin: 0 auto;"
	\|[[File:diagramPERT6.PNG \|200px\|thumb\| Example of two events when calculating the critical path in the PERT diagram]]		\|[[File:diagramPERT6.PNG \|200px\|thumb\|Fig. 6. Example of two events when calculating the critical path in the PERT diagram]]
	\|[[File:diagramPERT7.PNG \|200px\|thumb\| Example of events with the same predecessor when calculating its final point in the PERT diagram]]		\|[[File:diagramPERT7.PNG \|200px\|thumb\|Fig. 7. Example of events with the same predecessor when calculating its final point in the PERT diagram]]
	\|}		\|}