Program evaluation and review technique based on Petri nets and moment generating function

Classic program evaluation and review technique(PERT) do not allow the existence of loop in activity on arrow(AOA), and it should assume that all the activities time subject to the β probability distribution. These two restrictions limit the use of PERT. By mapping AOA network, this paper establishes the Petri nets based plan model that not only maintain the original properties of AOA, but also allow the existence of the loop. Meanwhile, combined with the analysis approach for Petri nets reachability graph and based on reducing the vanishing states of reachability graph, the performance parameters of PERT model can be calculated by introducing moment generating function (MGF). Finally, this paper verifies the applicability of this method for enhancing PERT by comparison of calculation instance with simulation experiment.