Types of dependencies

In a traditional Gantt scheduling the link between activities or tasks are called dependencies, there are 4 types:

• Finish-Start (FS)
• Start-Start (SS)
• Finish-Finish (FF)
• Start-Finish (SF)

By defining the dependency between Start and Finish dates you are defining the type of link between activities or tasks. For example, the "Contact caterers" task must finish before the start of the "Determine menus" task.

Table1.-Task dependencies

Graph	Task dependency	Description
	Finish-Start (FS)	Task (B) cannot start until task (A) finishes
	Start-Start (SS)	Task (B) cannot start until task (A) starts
	Finish-Finish (FF)	Task (B) cannot finish until task (A) finishes
	Start-Finish (SF)	Task (B) cannot finish until task (A) starts