Steps in Carrying Out Design FMEA

The following are steps for carrying out Design FMEA:

• Choose a system, sub-system or part and identify its functions.
• List potential failure modes.
• List potential effects of the failure.
• Approximation the Severity number (S).
• List potential causes or mechanisms of failure.
• Compute approximately the Occurrence number (O).
• What design verification measures were taken (for example prototype testing, pilot run, etc).
• Estimate the Detection number (D).
• If D > 5, take closure look at measures for detection (D > 5 implies high risk).
• Calculate the RPN.
• Can the system fail because of customer abuse or other in-use condition? If so, re-estimate S, O, and D and re-compute RPN.
• List suggested actions where applicable to lower RPN.
• List individuals (or departments) responsible for completing recommended corrective actions.
• List real actions taken.
• Re-compute RPN after corrective actions are implemented.
• Repeat all the steps above for all systems, sub-systems & components which are deployed in the product.

A broad guideline for severity, occurrence and detection ratings levels for design FMEA is as illustrated in Table.

                                                                       Table: Severity Level