How to perform a MSA - GRR (Gage R&R) A&R/ANOVA Vs GUM/VDA




We have no specific internal guidelines how to perform a MSA, and our customers have no special requirements either.

So far I have been using AIAG MSA A&R and ANOVA

Recently I have played with GUM according to VDA as well by transferring EV and AV from the GRR to the GUM and add the contribution from linearity/bias/resolution/stability/calibration uncertainty/temperature and then do the calculations.

The reason why I am interested in the GUM is that I wonder if I could make an uncertainty budget for the equipment rather than a process, which would make it more general and not as specific as the GRR would be.

A GRR would relate to a specific equipment+tolerance+operators (at least operators that are skilled equally) and most likely also the part - and would answer if it is able to verify the very specific product and/or process
Example: GRR<10%

A GUM would relate to the to the equipment and conditions (like temperature) at its worst - and would anser the uncertainty of the equipment
Example: 150mm +/-0,06

I am tempted to use the GUM as it would require fewer conducted MSA´s

Surely I am missing something..
Any useful comments about advantages/disadvantages much appreciated!


Super Moderator
A Quick Bump!

Can someone help a Fellow Cover?

Thank you very much!
Last edited:
Top Bottom