Reliability Analysis of Switches and Crossings – A Case Study in Swedish Railway

It is reported that switches and crossings (S&C) are one of the subsystems that cause the most delays on Swedish Railways while accounting for at least 13% of maintenance costs. It is the main reason for choosing to base this study on this subsystem. Intelligent data processing allows understanding the real reliability characteristics of the assets to be maintained. The first objective of this research is to determine the S&C reliability characteristics based on field data collection. Because field failure data are typically strongly censored, an especial statistics software package is developed to process field failure data, as commercial packages have not been found satisfactory in that respect. The resulting software, named RDAT® (Reliability Data Analysis Tool) has been relied upon for this study. It is especially adapted for statistical failure data analysis. In the next step the availability of studied switches and crossings is estimated based on the reliability characteristics founded in the first step.