Determining MSA (Measurement Systems Analysis) Frequency

[Forrest]

MSA Frequency

At what frequency should the MSA be repeated?
Our QS 9000 auditor (UL) has ask this question, & we do not have a stated frequency for repeating MSA.
Can anyone provide guidelines or suggestions?

 

[Marc]

Typically once a year or any time a change is made which will affect the gage or whatever.

 

[Atul Khandekar]

Once a year sound too gross to me.

Shouldn't you conduct R&R after every calibration?

Help ...

 

[Geoff Cotton]

Atul,

We have over 2,000 variable gauges on site, to do GR&R studies on all of them once a year is an impossible task.

We handle the problem by working to an 'audit schedule' where each TYPE of gauge is reviewed at least once per year. The gauge to be reviewed for the audit period is selected at random.

We also carry out two GR&R studies as part of our 6 Sigma projects. These are over and above the one carried out as per the schedule.

Geoff

 

[Marc]

Originally posted by Atul Khandekar:

Shouldn't you conduct R&R after every calibration?

You really have to look at the over all use of the gage, its stability and such. For example - If you have a fairly stable gage and your cal cycle is every 6 months I'm not sure an R&R after each calibration will buy you anything. The R&R should not change after a calibration. If you wanted some useful info, you might do an R&R just after a calibration and then another one just prior to the next calibration.

Are you currently doing an R&R after every calibration?

 

[Atul Khandekar]

Geoff , Marc

Yes, i would like to agree with what you are saying.

Actually, i'd much prefer to calibrate an instrument based on stability study. And since calibraton involves some adjustments to the instrument, i thought r&r is in order.

I have come across customers who insist on submitting r&r results with each consignment.
I am not sure if 'Audit Cycles' would be acceptable to them.

So, the original question remains:
- At what frequency should the MSA be repeated?

Are there any definitive guidelines? At least any thumb rules?

 

[Stuart Andrews]

MSA Frequency

Hi folks!
I've read another thread on this subject from last year, but the question wasn't really answered. So I thought I'd ask the same question. http://Elsmar.com/Forums/showthread.php?t=1073

I've looked in the AIAG MSA book and haven't found anything definitive.

The problem I have is that a supplier to us has submitted an MSA for a gauge, and the study was performed in March 1992. In my opinion this isn't acceptable, but I can't really ask them to do it more frequently because in theory this may be acceptable to them (as they know the gauge).

But a 9 year frequeny for an MSA study is a bit excessive.

Does anybody have anthing substantive on this subject.

 

[Al Dyer]

Suart,

Not all that much definitive direction here, just a comment.

Stability is the measure of bias over time. My question to the supplier would be: How can you prove the stability of the gage over time if you have not performed any studies in ten years?

Sounds to me like the supplier is trying to get around the intent of the process. (please slap me for using the "I" word)

As the customer, you hold the big stick, depending on how big the supplier is!

ASD...

 

[Stuart Andrews]

Thanks Al!

Have you any thoughts on why such an important measuring tool has been left open ended?

What do the "Big 3" do? I find it surprising that guidelines for assuring stability over time aren't stipulated in the QS manuals?

Would you think 2 years would be acceptable?

Any thoughts people?

 

[Al Dyer]

Originally posted by Stuart Andrews
Thanks Al!

Have you any thoughts on why such an important measuring tool has been left open ended?

$$$$$$$$$$$$$$$$$$$$$$$$$$$

What do the "Big 3" do? I find it surprising that guidelines for assuring stability over time aren't stipulated in the QS manuals?

That's why I used the evil "I" word

Would you think 2 years would be acceptable?

Just a personal opinion, but I believe that stability studies should be ongoing for the life of the gage. Of course cost comes into play and I would have different frequencies for a CMM and a set of calipers. Much of it is also based on amount of use, If I use a gage every hour every day I would have tighter frequency that a gage that I use 3 times a year. Unfortunately a very subjective topic and as always, your customer will have their own views that should probably be resolved during contract review or product realization.


Any thoughts people?