Today we will discuss start-to-finish relationships in a project network diagram. This project management dependency is not as common as a finish-to-start relationship, but knowing about it will help you develop a sound schedule network diagram.
Let’s start by understanding the terminology.
A predecessor activity will be completed before another activity, logically.
A successor activity will be completed after another activity, logically.
A lead is when the successor activity starts before the completion of the predecessor activity. This is an advancement and is denoted by the “-” sign.
A lag is a delay between a predecessor and a successor activity. It is denoted by the “+” sign.
A project network diagram can have four types of dependency:
According to the PMBOK Guide, a start-to-finish (SF) relationship is “A logical relationship in which a successor activity cannot finish until a predecessor activity has started. ”
In simple words, the finish of a successor activity is dependent on the start of the predecessor activity.
Representation of Start-to-Finish Activity
Here is how a start-to-finish relationship is shown in a network diagram.
Here is how a start-to-finish relationship is shown on a bar or a Gantt chart.
Example of Start-to-Finish Relationship
Consider a construction project where you need to move to a new house. To be able to do this, the new house needs to be already built. This is an example of a Start-to-Finish relationship.
Consider another example.
A new accounts payable system (successor) has to start before the old accounts payable system can be shut down (predecessor).
Start-to-finish is rarely used in developing a scheduling network diagram. The successor activity cannot finish before predecessor activities start.
Here is where this post on the start-to-finish relationship ends. Please share your experience with using it in the comments section.