The Project Planning process area involves the following : 

      •Developing the project plan

      •Interacting with stakeholders appropriately

      •Getting commitment to the plan

      •Maintaining the plan

       Planning begins with requirements that define the product and project. 

       Planning includes estimating the attributes of the work products and tasks, determining the resources

   needed, negotiating commitments, producing a schedule, and identifying and analyzing project risks.

   Iterating through these activities may be necessary to establish the project plan. The project plan

   provides the basis for performing and controlling the project’s activities that address the commitments

   with the project’s customer. 

       The project plan will usually need to be revised as the project progresses to address changes in

   requirements and commitments, inaccurate estimates, corrective actions, and process changes.Specific

   practices describing both planning and re-planning are contained in this process area. 

       The term“project plan”is used throughout the generic and specific practices in this process area

   to refer to the overall plan for controlling the project.