Overlaps of process groups in a phase

The five process groups are not discrete, one-time events. They overlap and repeat inside every phase of the project life cycle. PMBOK shows this with the overlapping-process-group diagram: the groups form overlapping curves of activity over time within a phase.

Sketch

Initiating  |=====|
Planning       |==========|
Executing          |==============|
Monitor&Ctrl |=======================|
Closing                        |=====|
            start ---- time ---- end

Explanation

• Initiating is highest at the start of the phase and falls quickly.
• Planning begins after initiating and continues; it peaks early and is revised throughout.
• Executing rises as plans are approved, peaks in the middle and falls as work ends.
• Monitoring and controlling begins early and runs for the entire phase, covering all groups.
• Closing rises near the end of the phase.
• The overlap means that planning is still in progress as execution starts, and control is being done while work happens.

Key points

• Each phase of the project life cycle (concept, development, implementation, close-out) goes through all five groups.
• The output of the closing group of one phase is the input to initiating of the next phase.
• Process groups are not the same as phases: phases divide the life cycle, while process groups divide the management processes.

Example: In the design phase of a software project, the team initiates (approves design work), plans (design schedule), executes (draws the design), controls (reviews) and closes (design sign-off).