Integrated Optimization of the Location–Inventory Problem of Maintenance Component Distribution for High-Speed Railway Operations

Dezhi Zhang,Shuxin Yang,Bin Ji,Jiajun Fan,Shuangyan Li

doi:10.3390/su12135447

Abstract

Sustainable distribution network design for the maintenance components of electric multiple units (EMUs) is critical to reduce the problem of unreasonable resource allocation and capital occupation of high-speed railway (HSR) operations. Motivated by the above analysis, this study investigates the integrated optimization of the location and inventory of EMU maintenance component distributions. Aiming to improve the sustainable operation for high-speed railway, we proposed a corresponding nonlinear mixed-integer programming model to determine the location of the distribution center (DC) for EMU maintenance component delivery, inventory control strategy, and corresponding service level. The above optimization model is solved by an adaptive improved genetic algorithm. The proposed model and algorithm are applied to a real-world case study on China’s EMU maintenance components. The findings show that a higher service level is not better to achieve the lower total cost in the maintenance component distribution network. The ratios of transportation modes are significant to balance the service level and total cost of the EMU distribution network. Furthermore, the unit out-of-stock cost and the service level both show great impacts on the total costs of the EMU distribution system. Finally, there exists an optimal ratio of different transport modes, which ensures the least total cost of the EMU distribution system.

Highlights

As a new method of transportation, high-speed railways have attracted extensive attention in recent years
The findings show that (i) adjusting the service level can achieve the purpose of reducing the total cost of the distribution network, but the concept of safety first does not apply to the inventory, and the higher service level is not better
The findings show that (i) there is a correlation between unit stockout cost and optimal service level

Summary

Introduction

As a new method of transportation, high-speed railways have attracted extensive attention in recent years. By the end of 2019, China had built a high-speed rail system of 35,000 km, which is more than 2/3 of the total length of all global high-speed rail systems [1,2]. Along with the construction of high-speed rail networks, the demand for electronic multiple unit (EMU) trains is increasingly strong. As of early 2019, the China Railway Administration owned 2827 EMU trains, an increase of 11.3% year-on-year. The first high-speed line was the Beijing–Tianjin high-speed rail line, which was put into operation in 2008 [3]. The long-term plan for high-speed railway networks and the current macroeconomic background raise concerns for scholars and managers regarding the distribution network design of maintenance components for high-speed railway operation

Methods

Findings

Discussion

Conclusion