A METHOD FOR ASSESSING THE CRITICALITY OF FAILURES OF RAILWAY VEHICLE COMPONENTS USING THE FMECA METHOD

Assessing the risk of hazards in the operation of rail vehicles is an important part of verifying their reliability and safety. This paper presents an example of the application of the Failure Mode and Effects Analysis included in dedicated railway standards, extended to the Failure Mode, Effects and Criticality Analysis with additional criticality factors. This extension allows for the assessment of the risk of failures of assemblies, subassemblies, and components of rail vehicles. Compared to the Failure Mode and Effects Analysis method, the Failure Mode, Effects and Criticality Analysis method introduces the indicators, such as: failure mode criticality, criticality of component, criticality of subassembly, and the criticality of assembly. It enables the more precise identification of critical components, subassemblies, and assemblies of the rail vehicles. This precision is crucial for planning preventive actions and maintenance strategies. The new method can be used to validate the results of classical Failure Mode and Effects Analysis using the indicator of failure mode criticality, which relies on the actual failure frequency function obtained from the reliability model of individual failure modes. This would increase the accuracy of the analysis and allow for a better representation of the systems actual behavior. The extended Failure Mode, Effects and Criticality Analysis method enables a more comprehensive criticality analysis, considering not only the value of criticality indicators but also their quantities in the reliability hierarchical structure of the analyzed wagons.