FMEA Ratings – What They Mean and Why Most People Set Them Incorrectly

There is a high likelihood that every FMEA you have ever created has one or more rating columns filled out incorrectly and as a result the effectiveness of your FMEAs is greatly reduced!

The primary purpose of the Design FMEA and Process FMEA is to enable companies to efficiently manage risk. No company has unlimited resources. When properly used the Design FMEA and Process FMEA help companies target the use of their limited resources to achieve the greatest reduction in design and manufacturing related risk. To be used effectively as risk management tools, one must properly populate the rating columns of the Design FMEA and Process FMEA. If you have participated in the creation of a Design FMEA or Process FMEA there is a high likelihood that you have spent considerable time populating the rating columns. More importantly, there is a 99% probability you have filled out one or more of the rating columns incorrectly.

Did you know:

• Every major national and international FMEA Manual/Standard/Guideline in publication including the latest AIAG-VDA FMEA Handbook instructs the users to populate one of the most important rating columns in both the Design FMEA and Process FMEA incorrectly
• RPN and SxO calculations should not be used to determine what to work on in a Design FMEA or Process FMEA
• Many replacements for the RPN such as the new AIAG-VDA FMEA Handbook’s “Action Priority” share some of the weakness of RPN and should not be used if you want to effectively target your resources at the highest risk issues
• Design engineers should never identify “Special Characteristics” for the Process FMEA Class Column for manufacturing personnel and why this one act costs manufacturing companies millions of dollars
• Contrary to what many FMEA “experts” teach, there is NO link between special characteristics in the Design FMEA and Process FMEA Class columns
• The removal of the Class column from the Design FMEA in the AIAG-VDA FMEA Handbook damages the effectiveness of the Design FMEA as a design risk management tool
• The latest ratings in the AIAG-VDA FMEA Handbook leads to both increased FMEA creation time with a proportional decrease in FMEA effectiveness