11 Failure mode and effects analysis
A failure modes and effects analysis (FMEA) is a initial approach to quantifying risk and thinking about mitigating options. It is a design approach for assessing risk associated with how parts of a system or the system as a whole can fail, identifies the consequences of failure, and provides a framework for revising the design and reducing risk. Remember, risk can be reduced by either decreasing frequency, reducing consequences, or both. Design techniques could include multiple barriers to failure; i.e., defense in depth and instituting redundancy and diversity.
How to execute FMEA
FMEA procedure
- Construct a detailed flow chart of the process.
- Determine how each step could possibly fail.
- Determine the “effects” of each possible failure.
- Assign a Severity Rating for each effect.
- Assign an Occurrence Rating for each failure.
- Calculate and prioritize a Risk Priority Number (RPN) for each failure.
- Review the process and conduct a root cause analysis.
- Take action to eliminate or reduce the Risk Priority Number.
- Recalculate the resulting RPN as the failure modes are reduced or eliminated.