Program Evaluation and Review Technique. A project management technique for determining how much time a project needs before it is completed. Each activity is assigned a best, worst, and most probable completion time estimate. These estimates are used to determine the average completion time according to the PERT Weighted Average Formula:
(Optimistic Estimate + (4 times Most Likely Estimate) + Pessimistic Estimate) divided by 6.
The average times are used to figure the critical path and the standard deviation of completion times for the entire project .