A heuristic for constructing activity-on-arrow pert networks with minimal dummy activities

A Project is an enterprise consisting of a set of activities which are required to be carried out in some specific order. The activities and the order in which they are to be carried out can be represented by a PERT network. Two types of networks are commonly used: Activity-On-Node (AON) and Activity-On-Arrow (AOA) networks. When AOA networks are used, it often becomes necessary to draw dummy activities. Since the computation of project completion time is proportional to the number of activities (including any dummy), it is desirable to draw a network with as few dummy activities as possible. Earlier studies have shown that the minimum-dummy-activities problem is NP-complete. This paper proposes a heuristic to construct PERT networks with as few dummy activities as possible. The heuristic is explained by an illustration.