Robust project scheduling based on the integrated optimization between resource flow network and time buffers

For solving the resource constrained project scheduling problem (RCPSP) with stochastic durations, robust resource allocation and time buffer insertion are combined effectively. A two-stage integrated optimization algorithm is proposed to generate robust project schedules against disruptions. In the first stage, a myopic expected penalty cost (MEPC) procedure is designed to construct a stable resource flow network by efficiently allocating resources among project activities. To further improve the schedule stability, an expected penalty cost (EPC) algorithm that relies on the fixed resource flow network is proposed in the second stage to minimize the expected penalty cost through inserting time buffers in front of the activities with higher delay risks. Finally, extensive computational experiments are performed to verify the feasibility and effectiveness of the two-stage algorithm from two aspects of solution robustness and quality robustness. The results indicate that the project schedule generated by the integration of the resource flow network and time buffers not only can achieve shorter completion times, but also can deal with disruptions more effectively during project execution. © 2018, Editorial Board of Journal of Systems Engineering Society of China. All right reserved.