Maintenance scheduling at high-speed train depots: An optimization approach

Abstract

Under the preventive maintenance policy, high-speed trains need to conduct periodical inspection/overhaul at dedicated depots, where maintenance facilities and maintenance crews are available. Due to the complicated structure of trains, the maintenance work is rich in a variety of types, characterized by mechanical components repaired, maintenance levels and etc. In practice, these types of maintenance work are integrated into maintenance packets, and different packets may require the specific types of crews. In this paper, a mixed integer linear programming model is proposed for the depot maintenance packet assignment and crew scheduling problem. The objective of the problem is to minimize the overall crew worktime, while the main constraints include the compatibility between maintenance packets and crew types, maintenance packet duration time and execution order, maintenance time window, and crew worktime limit. Besides, two families of valid inequalities are proposed to improve the baseline model. Computational experiments on a set of randomly generated instances show the effectiveness and efficiency of the improved model compared to the baseline one. Finally, a real-world case study from Shanghai South Depot is carried out to further validate the proposed approach. Improvements on both solution time and quality are achieved in contrast with the manual schedule.