RAMS Program for Electromechanical Systems of Railway Applications

The article deals with selected problems, which are associated with reliability and safety assurance in the case of electromechanical systems of railway applications. The authors of the article have long-term co-operation with LEKOV Company (Czech Republic), which is well-known producer of electric switching and controlling components for railway vehicles. To be successful in competition and satisfy high requirements of customers (major manufacturers of traction vehicles) the company, among others, pays exceptional attention to reliability and safety of its products. The article describes an integrated reliability, availability, maintainability and safety (RAMS) program which was worked out and established for development and design to fulfil demanding reliability and safety requirements of customers. The main methods, which are used as parts of the program, are preliminary hazard analysis, failure mode, effects and criticality analysis (FMECA), fault tree analysis (FTA), reliability block diagram analysis (RBDA) and reliability testing. The methods are used in individual steps that logically connect methods each to other. The article describes the procedures of the program in detail and brings a survey of applied methods with characterizations. Particular attention is devoted to problems that are associated with estimation of reliability measures of individual parts of systems.