What Is a PERT/CPM Chart?
The Program Evaluation Review Technique (PERT) was developed by the U.S. Navy to
manage very complex projects, such as the construction of nuclear submarines. At
approximately the same time, the Critical Path Method (CPM) was developed by private
industry to meet similar project management needs. The distinction between the two
methods has disappeared over time, and today the technique is called either PERT,
CPM, or PERT/CPM. The textbook will use the term PERT chart.
PERT is a bottom-up technique, because it analyzes a large, complex project as a series of
individual tasks. To create a PERT chart, you first identify all the project tasks and estimate
how much time each task will take to perform. Next, you must determine the logical order
in which the tasks must be performed. For example, some tasks cannot start until other tasks
have been completed. In other situations, several tasks can be performed at the same time.
Once you know the tasks, their durations, and the order in which they must be performed, you can calculate the time that it will take to complete the project. You also can
identify the specific tasks that will be critical to the project’s on-time completion. An
example of a PERT chart, which Microsoft calls a network diagram, is shown in the
lower screen in Figure 3-7.