Failure Modes, Effects and Criticality Analysis (FMECA) is a systematic engineering technique used to identify how individual components or subsystems can fail, evaluate the consequences of those failures, and prioritise them according to their severity, likelihood of occurrence, and detectability.

Unlike Fault Tree Analysis (FTA), which starts with an undesired system event and works backwards to identify its causes, FMECA begins at the component level and works upwards to assess the impact of each potential failure on the overall system.

In railway engineering, FMECA is widely applied throughout the design, verification, operation, and maintenance of rolling stock, signalling, traction power, communications, and infrastructure systems. It enables engineers to identify safety-critical components, prioritise maintenance activities, reduce operational risks, and improve overall system reliability.

FMECA is a key methodology within RAMS (Reliability, Availability, Maintainability and Safety) engineering and is commonly used alongside FTA to provide a comprehensive understanding of both failure causes and their operational consequences.

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IEC 60812 – Failure Modes and Effects Analysis (FMEA and FMECA)
EN 50126 – Railway Applications – RAMS Specification and Demonstration
EN 50129 – Railway Applications – Safety-related Electronic Systems for Signalling
IEC 61025 – Fault Tree Analysis (FTA)
ISO 31000 – Risk Management