Calculation of safe float use in risk-analysis-oriented network scheduling

One of the criticisms of the PERT/CPM technique is that it ignores the uncertainty influence of noncritical activities on project-duration estimation. As a result of this problem, the PERT/CPM technique gives an optimistic estimation of project duration and float use. The paper introduces a new concept of time-disturbance analysis for a project network. Time-disturbance analysis is a process of simulating the change of the expected time of a given merge event or total project duration with the changes in float use of noncritical activities. The computations of the late start and finish times of the noncritical activities on the basis of the rational use of the float are introduced by using the back-forward uncertainty estimation (BFUE) procedure, an analytical risk-analysis model. Time-disturbance analysis can assist in project scheduling to reduce project risks rationally.