Research on forecast model of schedule risk for project of uncertain network

This article has come up with new forecast model and method for PERT network time risk for project learning from Soroush´s critical path method. Considering the probability of common paths becoming critical ones and its affect on the earliest completing time of node to expected value and square deviation. It has not only improved the precision of calculation, but also has leading significance to the application of evaluation for network planning time risk for project.