RESEARCH ARTICLE Electric multiple unit circulation plan optimization based on the branch-and-price algorithm under different maintenance management schemes Wenjun Li1, Lei Nie1*, Tianwei Zhang2 1 School of Traffic and Transportation, Beijing Jiaotong University, Beijing, China, 2 School of Traffic and a1111111111 Transportation, Shijiazhuang Tiedao University, Shijianzhuang, China a1111111111 *
[email protected] a1111111111 a1111111111 a1111111111 Abstract For railway operators, one of many important goals is to improve the utilization efficiency of electric multiple units (EMUs). When operators design EMU circulation plans, EMU type OPEN ACCESS restrictions are critical factors when assigning EMUs to the correct depots for maintenance. Citation: Li W, Nie L, Zhang T (2018) Electric However, existing studies only consider that EMUs are maintained at their home depots. multiple unit circulation plan optimization based on However, targeting that problem, in this paper, an optimization model for the EMU circula- the branch-and-price algorithm under different tion planning problem that allows depots to be selected for EMU maintenance is proposed. maintenance management schemes. PLoS ONE 13 (7): e0199910. https://doi.org/10.1371/journal. This model aims at optimizing the number of used EMUs and the number of EMU mainte- pone.0199910 nance tasks and simultaneously incorporates other important constraints, including type Editor: Halife Kodaz, University of Konya Technical, restrictions, on EMU maintenance and night accommodation capacity at depots. In order to TURKEY solve the model, a branch-and-price algorithm is also developed. A case study of a real- Received: August 21, 2017 world high-speed railway was conducted to compare and analyze the effects of different maintenance location constraints.