Specify Predecessors and Successors Given a List of Project Activities
This is the first step to creating a Precedence Diagram (Project Network Diagram). In this step, the project activity dependencies are identified. The Precedence Diagram (Project Network Diagram) needs to clearly illustrate these dependencies.
While creating a list of project activities, you need to ask yourself the following questions:
What project activities happen before the activity being examined?
- What project activities can happen at the same time with this activity?
- What project activities happen after this activity?
For example, suppose you are constructing a shed and the following activity list has been defined:
Purchase Wood; Hire Workers; Dig Foundation; Lay Foundation; Harden Foundation Cement; Purchase Plot; Select Design; Assemble Shed; Purchase Paint
Suppose, you are examining the Purchase Wood activity. Ask yourself the three questions list above.
What project activities happen before the activities being examined? Some activities that may occur before the “Purchase Wood” activity include: Purchase Plot and Select Design
What project activities can happen at the same time with this activity? Some activities that may occur at the same time as “Purchase Wood” activity include: Hire Workers and Purchase Paint
What project activities happen after this activity? Some activities that may occur after the “Purchase Wood” activity include: Assemble Shed.
From the answers, we have determined the predecessors and successors of the Purchase Wood activity. Similarly, you can examine each project activity and develop relationships between each one (see the image below - click for a larger view). You will then have table of project activities, which also contain information about predecessors and successors.
The activity list would contain the entire scope. Generally, the scope of work that needs to be completed is broken into more manageable phases (releases and iterations). Each phase will have its own Precedence Diagram (Project Network Diagram). Prioritizing scope that provides maximum value is important. Read the Scope Prioritization Using Risk and Value article for more information.