Phased Mission System-Based Reliability Analysis of Scheduling Tasks in Railway Marshalling Station

The success execution of the scheduling tasks in a marshalling station is crucial to the whole railway transportation, which is the bottleneck of the railway network. However, the reliability performance evaluation of the scheduling tasks quantitatively are not performed yet. In order to tackle this problem, a Phased Mission System (PMS) modeling methodology is proposed to describe the tasks as several consecutive phases, which enables quantitative evaluation of each phase with heterogeneous configurations among phases. In the paper, the work flow inside a marshalling station is analyzed first. Then the fault tree models of different phases are constructed considering the functional relation of subsystems and equipment. The numerical analysis is carried out based on the Binary Decision Diagram (BDD) calculation method, according to relevant reliability parameters of the basic equipment. A case study is conducted to illustrate the evaluation process with a marshalling station layout from both local railway administration and marshalling station view. The result shows that the number of outdoor equipment have big influence to the scheduling tasks and the fault tolerant design helps to improve the performance during phases.