An Algorithm for Shunting Scheduling Problems combining Probabilistic Local Search and PERT

Shunting scheduling problems in railway stations can be regarded as a sort of resource constrained project scheduling problems (RCPSPs). But unlike normal RCPSPs, shunting scheduling problems have such requirements that the number of works which consist of a project has to be dynamically changed in the process of solving the problem, some of the works have to be performed at prescribed timing, etc., We propose an efficient algorithm for shunting scheduling problems combining probabilistic local search and PERT. Local search and PERT is combined so that the candidates for answers in the local search process are evaluated by PERT. This enables to reduce the search space of the local search to a great extent and to make the algorithm work quite fast. We have confirmed effectiveness of our algorithm through several experiments using practical train schedule data.