Failure Mode Effects Analysis

Failure Mode Effects Analysis (FMEA): This is another of those “scary” quality tools that people often don’t utilize strictly because they don’t really understand them. A Failure Mode Effects Analysis is simply a step-by-step attempt to identify all possible failures in a product, design or process. If it is being used for a process it is called a pFMEA and for design use a dFMEA. This method uses a model to prioritize each potential failure based on their severity, expected frequency, and likelihood of detection. This tool should highlight any actionable weaknesses that will improve robustness and drive continuous improvement. Developed in the 1940s by the US military, Failure Mode Effects Analysis was further developed by the aerospace and automotive industries and has now gained widespread acceptance.

The 10 Steps to developing a FMEA are:

Step 1: Review the process—Use a process flowchart to identify each process component.

Step 2: Brainstorm potential failure modes—Review existing documentation and data for clues.

Step 3: List potential effects of failure—There may be more than one for each failure.

Step 4: Assign Severity rankings—Based on the severity of the consequences of failure.

Step 5: Assign Occurrence rankings—Based on how frequently the cause of the failure is likely to occur.

Step 6: Assign Detection rankings—Based on the chances the failure will be detected prior to the customer finding it.

Step 7: Calculate the RPN—Severity X Occurrence X Detection.

Step 8: Develop the action plan—Define who will do what by when.

Step 9: Take action—Implement the improvements identified by your PFMEA team.

Step 10: Calculate the resulting RPN—Re-evaluate each of the potential failures once improvements have been made and determine the impact of the improvements.