1. Initiating: define the project, get authorization, identify stakeholders. 2. Planning: develop project plan, define scope, schedule, budget, risk plan. 3. Executing: coordinate people and resources to carry out the plan. 4. Monitoring & Controlling: track, review, and regulate progress; manage changes. 5. Closing: formally complete the project or phase, obtain acceptance, archive. Note: These are process groups, not phases. Multiple process groups can occur within a project phase.