This paper was published in IRSE NEWS December 2017.

Good reliability is a key requirement of any railway or metro system. Many rail networks throughout the world are the most reliable they have ever been, but also the busiest, so any asset failure has a bigger impact on performance. Asset reliability is therefore of even greater importance in delivering a reliable railway. Signalling and communications assets have a major impact on the overall reliability of a railway and this article discusses some of the issues and techniques that should be considered to improve asset reliability.

The first step in improving reliability is to identify the root cause of any failure. It is vital to understand how and why assets fail so that interventions, maintenance practices and techniques can be developed to make the infrastructure better and more resilient.

Various levels of peer review and analysis should be used to determine the immediate and root cause of failures, and what lessons can be learned to prevent similar and repeat failures. Reliability specialists should guide maintenance mangers and engineers to carry out root-cause analysis and gather data for the investigating process. This includes collecting data through interviews and analysis, together with applying techniques to identify and know the difference between symptoms and root causes. The objective is always to learn how to avoid future incidents by developing appropriate recommendations to address causal factors and root causes as well as, where appropriate, developing processes to identify systemic problem areas.