Auditor wants our Gage R&R Procedures to address Linearity, Accuracy and Stability

We have our R & R procedures and work instructions operating smoothly. Can anyone offer any assistance on what they are currently doing with linearity, accuracy, and stability as defined in the MSA manual?

Are you using specifically-written procedures and/or work instructions for these activities?

Are the auditors looking at these items closely during audits?

Thanks in advance for any advice or assistance and/or samples you can offer.

[Marc]

You might first want to read the following thread from the 'old' board:

Bias, Linearity and Such - from the old forums.

Mr. Adamek and I had a somewhat extended 'conversation' to which I admit I was pretty hard headed... I think he got mad at me...

In addition, you might want to check out:

Some Calibration - MSA related tidbits

The bottom line is auditors are beginning more and more to address MSA issues. They want to see evidence of understanding and utilization of MSA concepts. It would probably be wise about now to consider a procedure explaining how you address linearity and bias and such. It could be very simple and along the precepts of what is in the threads hot-linked in this message reply.

By the way - Did you know Gage R&Rs are not *mandatory*???

Hope this helps!

The UL auditor that just left our facility looked very closley at MSA and wrote us up for not measuring and trending stability. What he wanted to see was the past calibration results plotted for each instrument. I havent fully checked this out but it seems excessive. We were going the obligatory GR&R studies so we are still looking into the validity of this Action request.

[Marc]

Bill - My opinion is that is a crock of ----. Where does it say you have to trend on paper? If the calibration person has half a bean of intelligence s/he can easily look at the numbers and understand what is happening without putting together a graph. I just went thru this with LRQA in May. They didn't require a graph - but they did want the cal folks to prove that they considered this at each calibration and that the concept is understood.

UL is known to be asinine about MSA - But, other registrars are hitting it more now too. I will admit that many, many companies do not have people who really understand MSA, but the auditors are getting rediculous.

Bias and Linearity should be known before you do a GRR study. My company has a procedure for MSA, that includes GRR. In fact, GRR is one of the last, if not the last step in an MSA study. As far as stability is concerned, the procedure gives the QA Manager the responsibility to decide if a stability study is necessary. The QA manager's job description requires him (her) to have MSA and SPC training. Stability studies may not be necessary for computer controlled equipment or if the cost of the project outweigh the benefit.

[Marc]

I agree with you 100% Christian. You are looking at MSA as a high order system - which it is. R&R is done late in the game. It sounds like you have a well written procedure. I'd love to see it.

[David McGan]

Christian, when you're e-mailing a copy of your procedure to Marc, copy me in also. Or just post it here for all of us to read.

[Marc]

Also see http://Elsmar.com/Forums/showthread.php?t=1009