Time-Cost Tradeoff Analysis in Project Management: An Ant System Approach

The time-cost tradeoff problem (TCTP) is an important issue in the scheduling of industrial projects; it is often possible to expedite the completion of certain activities by increasing the budget. This paper develops a new approach for the discrete TCTP (DTCTP) in program evaluation and review technique networks of project management, in which activities have multimode discrete cost functions and activity durations are normally distributed. Moreover, the first application of the ant colony system (ACS) is applied to the stochastic DTCTP, solving it as a nonlinear zero-one problem. To illustrate the suggested approach, a numerical example is discussed and an overall efficiency measure is developed to set the ACS parameters so as to reach more accurate results with less computational time. The results obtained from the computational study demonstrate the effectiveness of the suggested approach for the DTCTP.