Using a multicriteria interactive approach in scheduling non-critical activities

A typical project consists of many activities. Logical dependencies cause some of them to be critical and some non-critical. While critical activities have a strict start time, in some projects the problem of selecting the start time of a non-critical activity may arise. Usually, it is possible to use the “as soon as possible” or “as late as possible” rules. Sometimes, however, the result of such a decision depends on external factors, e.g., an exchange rate. In this paper, we consider the multi-criteria problem of determining the start time of a non-critical activity. We assume that the earliest start and the latest start times of the activity have been identified using the critical path method, but the project manager is free to select the time when the activity will actually be started. This decision, however, cannot be changed later, as it is associated with the allocation of key resources. The criteria that are usually considered in such a situation are cost and risk. We assume that the cost depends on an exchange rate. We also consider the risks of project delay and a decrease in quality. This paper formulates the selection of the start time for a non-critical activity as a discrete dynamic multicriteria problem. We solve it using an interactive procedure based on the analysis of trade-offs.