Analysis of the robustness of terminal turnaround arrangements for railways

The application of Lean principles to terminus operations of high-speed railways has the potential of enhancing the efficiency of resource usage during both the construction and operation periods, through faster turnarounds and, hence, a reduced space requirement thanks to fewer platform tracks being needed. However, this greater efficiency must not be allowed to result in less robust services. The robust design of products and processes has been studied extensively in the manufacturing industry. By contrast, the robustness of high level railway operational concepts and system design has been investigated rarely. In this study, Taguchi methods that originated in the manufacturing industry are applied to a robustness assessment of system designs in the context of railway operations. The approach is used to assess terminus designs with different numbers of platform tracks, layouts with particular conflict patterns, minimum required turnaround times and signalling facility capability. The authors use a Monte-Carlo simulation with statistical delay distributions. The simulation results show that the signalling system's capability is the most important factor in achieving high capacity and that the robustness of railway terminus operations is not affected by adopting faster turnaround and having fewer platform tracks at termini. Finally, some suggestions for future planning are presented.