Gage R&R Frequency required by TS 16949

[dbzman]

I am placing this question in the TS thread because it was a finding during our TS audit.

One of our finding was for having an old GR&R study(2004) for a hardness tester and not having a study for an MT-90 case depth machine. Both issues were listed as findings under the same Nonconformance.

Not having a study for the MT-90 is a legitimate issue but I am not sure about having an old study (2004). Is there a frequency that is required by the AIAG manual?

Thanks!

 

[Stijloor]

I am placing this question in the TS thread because it was a finding during our TS audit.

One of our finding was for having an old GR&R study(2004) for a hardness tester and not having a study for an MT-90 case depth machine. Both issues were listed as findings under the same Nonconformance.

Not having a study for the MT-90 is a legitimate issue but I am not sure about having an old study (2004). Is there a frequency that is required by the AIAG manual?

Thanks!

No, the MSA manual does not "prescribe" a frequency, but how much confidence do you have in a measuring system that is 4-5 years old? Are you sure that nothing in that system has changed? "People" perhaps?

Stijloor.

 

[dbzman]

No, the MSA manual does not "prescribe" a frequency, but how much confidence do you have in a measuring system that is 4-5 years old? Are you sure that nothing in that system has changed? "People" perhaps?

Stijloor.

Good point!
We are a heat treating company so we have had some trouble with Gage R&R for our hardness testers. In the past we were told that the testers were essentially doing destructive tests and it would be hard to perform Gage R&R on them. Believe it or not, during our QS9000 days the auditors accepted this.
Now there has been more work in Gage R&R for hardness testers in the industry so we cannot rely on that reasoning. Old habits die hard. In the past we relied on the fact that our calibration would do the job and that we could not necessarily do statistical studies on the testers.

Now we are traveling down that road and trying to determine how to approach this. We will be conducting Gage R&R on the testers.

Thanks for the input!

 

[bobdoering]

I agree with Stijloor, Gage R&Rs do not have a "shelf life" when performed correctly (as in incorporating a large enough variation of user skills). However, many folks in automotive do not believe that, and you may find some customer specific requirements (not based on any solid reasoning) that may specify a year, especially for a PPAP submission.

 

[David DeLong]

No, the MSA manual does not "prescribe" a frequency, but how much confidence do you have in a measuring system that is 4-5 years old? Are you sure that nothing in that system has changed? "People" perhaps?

Stijloor.

Auditors usually get irritated when they see an old date on a report especially if it is a TS audit. I would suggest that once a year, someone should review the R & Rs of the various family of gauges reflected in the control plan. If they still look OK, I would suggest a reviewed date on the report replacing the original date. That way, a report would looked outdated.

If something on the gauge has changed or looks suspect, then I would suggest another R & R study to the latest AIAG format on that family.

I would also suggest that in your procedure on R & R studies, please do not have a fixed percentage which could paint oneself in a corner. I know that not all gauges will achieve 30% of the process. One might note a recommended percentage or "state of the art" which would be more realistic. I know that a Rockwell tester is one of those gauges that probably will not achieve the desired percentage.

An R & R study reflects the application of the gauge to the measuring process and changing Operators or "people" should not be a factor.

 

[bobdoering]

Let's ponder what the AIAG MSA 3rd edition actually says. On page 69 it notes Phase 1 and Phase 2 evaluation of a gaging system. Phase 1 answers the question "Is this the right gage for the job?" It only answers this question once, and Gage R&R is a part of Phase 1 analysis. Phase 2 seeks the ongoing monitoring of key sources of variation that may degrade over time. Of course, that is the job of calibration and stability.

They ask the question on page 72: "How often should Phase 2 be performed?" Their answer is not annually, but rather "it depends" (the correct answer to any question) on the statistical properties of the individual measurement system and the consequence to the facility...and so forth.

So, we ask the auditor again "Where does it say you have to do a Gage R&R annually in the standard? Where does it say how old is too old, if such a thing even makes sense?"

 

[Bev D]

I am one of those who abhors doing something just to make an auditor comfortable. I believe that one of the qualifications for being an auditor is enough intelligence, knowledge and common sense to understand the physics, geometry & statistics of the processes and situations that are being audited and what the actual requirements are as well as what their intent is. Given that we all have limited resources - and that is only getting worse - even a few minutes spent in non value add activity is shirking our corporate responsibility.

Phase 2 seeks the ongoing monitoring of key sources of variation that may degrade over time. Of course, that is the job of calibration and stability.

They ask the question on page 72: "How often should Phase 2 be performed?" Their answer is not annually, but rather "it depends" (the correct answer to any question) on the statistical properties of the individual measurement system and the consequence to the facility...and so forth.

I would add to that - actual process degradation. IF the measurement error of a gage/system deteriorates over time AND it's not caught at calibration THEN it woudl show up in product variation degradation. If the product variation is unchanged so is the measurement error for all practical purposes.

 

[dbzman]

I agree,

This issue was a result of a non-conformance to TS16949. We really should not let auditors findings stand if the finding is not (legitimately) written against the standard. Good practice is something that we should pay attention to but if an audit finding cannot be shown to be a violation of the standard then it should be appealed.
Id an auditor wants to document what he thinks would be a better practice then he should do it as an Opportunity for Improvement (OFI).

By the way, I heard that auditors will no longer be allowed to write OFI unless they have shown, through documented evidence, that the area for improvement is complaint to TS.

 

[AndyN]

Between this and the other finding (that was yours, wasn't it?) during the winessed audit, it seems like time for a change.

It worries me somewhat when audits behave like this and their management don't know of their biases. When I was a practicing CB auditor we did a lot of field supervisor reviews to ensure this wacky stuff got nipped in the bud.........no-one wanted to have me as their supervisor.....

 

[howste]

By the way, I heard that auditors will no longer be allowed to write OFI unless they have shown, through documented evidence, that the area for improvement is complaint to TS.

I think the word your were looking for was compliant. What you said is true:

Opportunity for improvement
An opportunity for improvement is a situation where the evidence presented indicates a requirement has been effectively implemented, but based on auditor experience and knowledge, additional effectiveness or robustness might be possible with a modified approach.