The Method of Programme Evaluation and Review Technique and Critical Path are explained below:
This network technique is used for planning and controlling of different functional areas of management. The network analysis process consists of analysing the individual jobs or events (i.e. the components of the large project) and arranging them in a logical network. Thereafter, these individual jobs or events are given time estimates for their execution.
The network thus helps identify the jobs or events which control the project’s completion. The network thus helps management complete the project on time by focusing its attention on the danger areas. It also fosters an optimum utilisation of all the resources that go into the project.
CPM or the Critical Path Method was developed by Morgan R. Walker of the Engineering Services Division of Dupont and James E. Kelly who was at that time with “Remington Rand.
They were concerned with the problems, of improving the scheduling techniques or projects such as the building of a pilot model plant and the shutdown of a plant for overhaul and maintenance.
They came up with the arrow diagram as the most logical representation of the inter-relationships between the jobs in a project to be executed in a well defined sequence.
The arrow diagram designed by them, as the method of calculating the critical path or the longest path through it, is the same as the PERT network and critical path calculation except that they used the single time estimate and did not enter the problem of uncertainty of the duration of time for the individual jobs.
Again PERT is more concerned with shortening of the project execution time rather than with cost. As against this CPM is more engaged in optimising resource allocation and minimising overall cost for a given project execution time.
PERT was developed in the U.S. Navy’s special Project Office through the recognition by Admiral W.R. Raborn of the need for something better in the form of an integrated planning and control system for the FBM (i.e. Fleet Ballistic Missile) programme, commonly known as the Polaris Weapons System.
A research scheme was established in 1958 to work on a project designated as PERT or Programme Evaluation Research Task. By the time the first Navy internal report emanated on the subject, PERT had become “Programme Evaluation and Review Technique”.