3 Main Limitations of Programme Evaluation and Review Techniques are given below:
1. Uncertainty about the estimate of time and resources. These must be assumed and the results can only be as good as the assumptions.
2. The cost may be higher than the conventional methods of planning 1 and control. Because of the nature of networking and network analysis, it requires a high degree of planning skill and greater amount of detail which would increase the cost in time and manpower resources.
3. It is not suitable for relatively simple and repetitive processes such as assembly line work which are fixed-sequence jobs. Hence PERT is not every effective in manufacturing operations since it deals in the time domain only and does not deal with the quantity information which is necessary in manufacturing processes.