Failure mode and effects analysis

FMEA

Failure mode and effects analysis

Failure mode and effects analysis (FMEA) is a systematic method for evaluating processes to identify where and how they might fail and assessing the relative impact of different failures, in order to identify the parts of the process that are most in need of change. It is widely used in various industries, including aerospace, automotive, manufacturing, and healthcare.

History

FMEA was first developed by the United States Armed Forces in the 1940s to improve the reliability of military equipment. It was later adopted by the aerospace industry and eventually spread to other sectors, including automotive and healthcare.

Types of FMEA

There are several types of FMEA, each tailored to specific applications:

• Design FMEA (DFMEA): Focuses on potential failure modes of a product's design.
• Process FMEA (PFMEA): Concentrates on potential failure modes in manufacturing and assembly processes.
• System FMEA: Evaluates potential failure modes within a system or subsystem.

Steps in FMEA

The FMEA process typically involves the following steps: 1. **Identify the process or product to be analyzed.** 2. **List potential failure modes.** 3. **Determine the effects of each failure mode.** 4. **Assign a severity rating to each effect.** 5. **Identify potential causes of each failure mode.** 6. **Assign an occurrence rating to each cause.** 7. **Identify current controls for each cause.** 8. **Assign a detection rating to each control.** 9. **Calculate the Risk Priority Number (RPN) for each failure mode.** 10. **Prioritize the failure modes for action.** 11. **Implement corrective actions and reassess the RPN.**

Risk Priority Number (RPN)

The RPN is a key metric in FMEA, calculated by multiplying the severity, occurrence, and detection ratings: RPN = Severity × Occurrence × Detection

Benefits of FMEA

• **Improves product and process reliability.**
• **Identifies potential failure modes early in the development process.**
• **Helps prioritize risks and focus resources on critical areas.**
• **Facilitates continuous improvement.**

Related Pages

• Reliability engineering
• Root cause analysis
• Quality control
• Risk management
• Six Sigma

See Also

• Fault tree analysis
• Hazard analysis
• Design for Six Sigma