According to the PMBOK® Guide (Project Management Body of Knowledge), project management is performed through the integration of processes. These processes are logically grouped into five categories known as the Project Management Process Groups.

These groups are independent of process phases and are applied to every project or project phase to manage the flow of work:

Initiating Process Group: Those processes performed to define a new project or a new phase of an existing project by obtaining authorization to start.

Planning Process Group: Those processes required to establish the scope of the effort, refine the objectives, and define the course of action required to attain the objectives.

Executing Process Group: Those processes performed to complete the work defined in the project management plan to satisfy the project requirements.

Monitoring and Controlling Process Group: Those processes required to track, review, and regulate the progress and performance of the project; identify any areas in which changes to the plan are required; and initiate the corresponding changes.

Closing Process Group: Those processes performed to formally complete or close the project, phase, or contract.

Process Groups vs. Knowledge Areas: While there are 5 Process Groups, there are 10 Knowledge Areas (such as Scope, Schedule, Cost, etc.).

Process Groups vs. Project Life Cycle: Process Groups are not the same as project phases. Most process groups will typically be repeated within each phase of a project ' s life cycle.

Continuous Nature: The Monitoring and Controlling process group occurs concurrently with all other process groups (except Initiating in some frameworks) to ensure the project stays on track.