A risk-based model for inspection and maintenance of railway rolling stock

Along with the widespread use of high-speed vehicles and increased traffic levels on the railroads, maintenance management of rolling stock assets is considered to be an area of high priority. In the past, the planning of inspection and maintenance activities for rolling stocks has been based on the accumulated knowledge and experience of asset owners, operators and manufacturers. However, current research efforts are focused on the development of risk-based maintenance approaches with the major goal of reducing life cycle costs while keeping a high level of safety and service quality. This paper presents a novel risk-based approach to inspection and maintenance management of the railway rolling stock assets. A quantitative model is developed to evaluate the risks associated with various types of failure of rolling stocks. To this aim, the root causes of failure are investigated and a probabilistic method is used to estimate the likelihood of occurrence of a failure. The failure consequences taken into account include the costs of inspection, maintenance and repair, the penalty charges due to train delays or service interruption, and the costs of loss of reputation in relation with train cancellations. For the purpose of clearly illustrating the proposed method, the risk-based analysis model is applied to a rolling stock passenger door system in a Scottish train operating company and the results are discussed. The model presented in this paper not only provides the capability to assess the current maintenance standards within the railway transport industry but also helps the maintenance engineers to propose or initiate improvement actions when needed.