An Alternative Approach to Railway RAMS: Development of an Extended RAMS Framework

Abstract

The management of a diverse asset portfolio is a demanding task for railway asset managers. They must ensure that the network delivers a high level of performance for customers and adheres to safety limits. Reliability, availability, maintainability and safety (RAMS) analysis is regularly used to assess the performance of systems, including railway networks. However, currently there are a wide range of different approaches to RAMS analysis in the railway industry. This research seeks to identify and consolidate any potential extensions to the traditional RAMS approach into a single framework: extended RAMS. The framework comprises ten parameters, RAMS and six additional parameters of particular interest to railway asset managers, including capacity and train performance. The framework is intended for use by asset managers to evaluate the attributes and current status of the railway infrastructure and enable comparison between different parts of the network and to evaluate different stakeholder needs. NotationA occupied (used) capacity B unusable capacity C recovery allowance D unused capacity f (x) probability density function M(t) probability that the component is repaired within time t R(t) reliability or assessment of how often failures occur a line speed adjustment time b station adjustment time g recovery allowance d unused capacity t maximum number of trains per hour Cite this article