Project Management Process Groups are linked by the outputs they produce.
The Process Groups are seldom either discrete or one-time events; they are overlapping activities that occur throughout the project.
The output of one process generally becomes an input to another process or is a deliverable of the project.
The Planning Process Group provides the Executing Process Group with the project management plan and project documents,
and, as the project progresses, it often entails updates to the project management plan and the project documents.
The following figure illustrates how the Process Groups interact and shows the level of overlap at various times.
If the project is divided into phases, the Process Groups interact within each phase.
In multi-phase projects, processes are repeated within each phase until the criteria for phase completion have been satisfied