Anyone who has done an online search using the terms “risk analysis,” “managing risk,” “risk management,” or any other variation will have discovered that the subject has been around for a long time and been covered by numerous authors. Still, the daunting challenge remains: How can one conduct process risk analysis without the help of a Ph.D. in statistics? 

FMEA fundamentals

A popular technique often invoked by various experts is failure mode and effects analysis (FMEA), developed several decades ago. This simple and controversial technique relies on the assignment of subjective ordinal numbers (usually using a 1–10 Likert-type scale) to estimate probabilities for three events:
• The difficulty (D) of detecting a failure
• The severity (S) of the failure
• The likelihood of occurrence (O) of the failure

These three subjectively estimated ordinal numbers are multiplied to “compute” risk priority numbers (RPNs) for various process steps. The RPNs are then ranked from highest to lowest, and the process steps with the highest RPNs are then analyzed to see how process improvements can be designed to help reduce the RPN—ideally to zero.

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