Programme Evaluation and Review Technique was developed in 1958 as a result of collaboration between the Operational Research Division of the United States Navy and a firm of business consultants. It was developed as a Management Aid for completing Poloris Ballistic Missile Project. It worked well in expediting the completion of the project from 7 years to 5 years. Since then, PERT has become a very popular technique used for project planning and control. It schedules the sequence of activities to be completed in order to accomplish the project within a short period of time. It helps in reducing both the time and cost of the project.
Advantages of PERT
1. It determines the expected duration of activities and consequently of the project duration.
2. It helps the management in handling the uncertainties involved in the project and thus reduces the risk element in the project.
3. It enables the management to make optimum allocation of limited resources.
4. It presses for the right action, at the right point and at the right time in the organisation.
5. It determines the most economical schedule for a fixed project duration.
Limitations of PERT
1. The time estimates to perform activities constitute a major limitation of this technique. If the estimates are not satisfactory then the network will be highly unrealistic.
2. The probability distribution of total time is assumed to be normal, which in real life situation may not be true.
3. The Simple PERT technique does not consider the resources required at various stages of the project. If a certain resource may be used to perform more than one activity and at the same time, it can be used for only one activity at a time, then the network diagram will become infeasible.
4. Use of this technique for active control of a project requires frequent updating and revision of PERT calculations and this proves quite a costly affair.