Path critical index and activity critical index in PERT networks

The criticality index of an activity is the probability that the activity is on the critical path of the network. The criticality index of a path is the probability that the duration of the path is greater than or equal to the duration of every other path in the network. In this paper, a new exact formula is presented to compute the path critical index and activity critical index for the PERT network with any structure. It is assumed that each activity duration time is a discrete random variable. Numerical examples presented in this paper prove the method is highly efficient and has excellent results compared to Dodin and Elmaghraby's approach.