In the development of a CPM Schedule, either the overall project duration is known, requiring task durations and sequencing to complete on time, or the task durations and sequencing are fixed and the overall duration is developed manually or by the algorithm in the software.

In order to shorten the overall duration of a project, critical path activities must be evaluated. Since task durations depend on resources, resources must be increased or some tasks must be started before all work of other tasks is completed.

While each project may be broken into phases, each phase must be analyzed to identify tasks and the required resources to complete each task. By so doing, an estimate of the time for completion may be obtained.

The example WBS and schedule shown in section 6 are for a project for which detailed design (engineering) was complete and construction was ready to be awarded. Even at this stage, however, engineering details or corrections are part of a project and usually preceded applicable tasks. As an example, the HVAC, Electrical, and Plumbing tasks will require, at least, purchase and manufacturing of components prior to installation. A more complete WBS and schedule would include these activities.

The following exercise will allow you to develop a schedule manually. Table 1 is an example of a WBS with an estimate of resources, duration, and sequence for each task, for the design of a new product.
Using this table, develop a Gantt chart, identify the critical path and estimate the completion date of the work. In order to prepare a schedule, a calendar is needed to convert the duration into calendar days. Combining Table 1 with the calendar results in Table 2. The results are shown in the Product Design Baseline Schedule.