Sounds of silence: A sampling-based bi-criteria harmony search metaheuristic for the resource constrained project scheduling problem with uncertain activity durations and cash flows

Abstract

In this paper, we present a new sampling-based bi-criteria hybrid harmony search metaheuristic for the resource-constrained project-scheduling problem (RCPSP) with uncertain activity durations (UAD) and uncertain cash flows (UCF), with the total project duration (TPD) and the net present value (NPV) as objectives. The proposed problem-specific Sounds of Silence (SoS) metaheuristic is an appropriate hybridization of the robust SoS developed to minimize the project makespan with uncertain activity durations, and the crisp SoS developed for several a primary-secondary (PS) and bi-criteria (BC) project scheduling problems. In the presented hybrid approach, we applied a sampling-based approximation to cope with the uncertain cash flows. In order to illustrate the efficiency and stability of the proposed problem-specific SoS, which is a new member of the SoS family, we present detailed computational results for a larger and challenging project instance. The computational results reveal the fact that the modified and extended SoS is fast, efficient and robust algorithm, which is able to cope successfully with the project-scheduling problems when we replace the traditional crisp parameters with uncertain-but-bounded parameters.