Planning, Scheduling, and the Scheduler

Project planning is a process within program management. An integral stage of management, it results primarily in an overall program execution strategy. The overall strategy is documented in the project plan, which defines, among other things,

• project scope;
• project objectives and requirements;
• stakeholders;
• organizational and work breakdown structures;
• design, procurement, and implementation; and
• risk and opportunity management plans.

Project planning is the basis for controlling and managing project performance, including managing the relationship between cost and time.

Scheduling is a distinct process that follows the planning process. The schedule is essentially a model of the project plan. It calculates the dates on which activities are to be carried out according to the project plan. As a model of time, the schedule incorporates key variables such as nonworking calendar periods, contingency, resource constraints, and preferred sequences of work activities to determine the duration and the start and finish dates of activities and key deliverables.

Planning and scheduling are continual processes throughout the life of a project. Planning may be done in stages throughout the project as stakeholders learn more details. This approach to planning, known as rolling wave planning, is discussed in Best Practice 3. Scheduling involves the management and control of the schedule over the project’s life cycle. However, in no case should planning be concurrent with scheduling. In other words, work and strategies for executing the work must be planned first before activities can be scheduled.

By creating and maintaining the schedule, a scheduler interprets and documents the project plan developed by those responsible for managing and for executing the work. The scheduler is responsible for creating, editing, reviewing, and updating the schedule and ensuring that project and activity managers follow a formal schedule maintenance process. Interpreting the project’s sequence of work entails responsibility for alerting program management to threats to the critical path, the degradation of float, and the derivation and use of schedule contingency. These concepts are discussed in Best Practices 6, 7, and 8. The scheduler must also modify the schedule in accordance with rolling wave planning details and approved change requests, including changes in scope and resource constraints. Maintaining a reliable schedule allows the scheduler to identify the effects of delayed activities or unplanned events on the planned sequence of activities, as well as possible mitigation strategies to prevent significant delays in planned work. The scheduler must track and report actual work performance against the plan, including the production of variances, forecasts, and what-if analyses.