Project management has evolved as a field with the development of two analytical techniques for planning, scheduling, and controlling of projects. These are the project
evaluation and review technique (PERT) and the critical path method(CPM).
These techniques were developed by two groups almost simultaneously. CPM was
developed by E. I. Du Pont de Nemours & Company as an application to construction
projects and was later extended to a more advanced status by Mauchly Associates.
PERT was developed by the U.S. Navy by a consulting firm for scheduling the
research and development activities for the Polaris missile program.
Although PERT and CPM were developed independently, they are similar in
principle. Today, PERT and CPM actually comprise one technique and the
differences, if any, are only historical. Consequently, both technique are referred to as
“project scheduling” techniques.
Project scheduling by PERT-CPM consists of three basic phases: