From "managing the critical path" to "managing critical activities"
A project manager's ability to successfully use mathematical models to realize projects involves not only their knowledge of the system's capabilities but also their understanding of the model's assumptions and limitations. This paper examines the implications of using the Program Evaluation and Review Technique (PERT) model, examining the information that project managers can and cannot obtain from PERT. It explains how PERT works, the validity of the activity completion information it provides, and the problems with relying on a single critical path for implementing projects. It then describes the managerial implication of using PERT, of what it is not designed to accommodate and what it can provide; it also suggests a redefinition of the notion of critical activities. It discusses a BASIC program for simulating PERT, one that uses a Monte Carlo process to generate activity durations in relation to activity distributions.