Semi-autonomous Framework for Propulsion Subsystem Overhaul and Refurbishment

Acquisition costs and increasing demand for rolling stock (RS) capacity often make replacement of ageing systems by operators challenging. The advent of innovative railway technologies such as the European Traffic Management System furnished with new software-based systems often require regular updates and component replacements, which leads to a mid-life overhaul and refurbishment (O&R) for most RS systems. In many instances, service-affecting failures and errors encountered after O&R projects are mainly due to over-reliance on engineering judgements of experienced maintenance staffs and sparse use of operational data, which are attributable to the lack of unified practice-based methodologies. The purpose of this study is to propose a modified hybrid model that can effectively support O&R activities at the end of life for an RS subsystem. The framework aggregates an upstream reliability and risk and downstream maintenance and overhaul technique as a single hybrid framework. With UK based railway operational and real- life data, the proposed technique was applied as a case study. The results showed that the modified hybrid model effectively addressed the reliability, risk and maintenance challenges posed by critical RS subsystems during O&R activities.