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?

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

Once a year sound too gross to me.

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

Help ...

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

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?

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?

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.

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...

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?

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?

Brilliant!

And thanks.

Stuart

Nine years is rediculous. The US auto industry via QS requires yearly studies. Al's first reply sums things up.

But... (Here I go again! :thedeal: ) In reality, you have to look at the gage and it's use. Is it only used twice a year on 5 parts for 10 total measurements? Or is it used to take 100 measurements a day? How critical is the measurement? Is it used on a production line or is it used in a lab? How is it protected? What type of gage is it? For example, how often would you want a gage R&R on an optical comparator? Or laser mics? Or a steel rule?

Remember that gage R&Rs only make sense in high volume situations with mechanical (or electro-mechanical {e.g. digital calipers}) measurement devices.

Give us some of these details and we can better address your specific situation.

Also see http://Elsmar.com/Forums/showthread.php?s=&threadid=3690

Thanks Marc

Your statement about "the Auto industry via QS" stating yearly, I'm not able to find that in writing. Would you be able to point me in the right direction, so I can quote it correctly to our suppliers.

Fortunately, our site is small enough to cope with doing them yearly, so I haven't got a problem with this frequency.

The problem arose because one of our suppliers submitted a PPAP with a gauge R & R study performed in 1992. Rather than argue the case for a more frequent study, I was hoping that something would be written down.

With the information I've been given already, I believe I would win that arguement, but you've led me to believe (now) that it is written somewhere.

Any thoughts?

I can't give you a text citation per se. I used QS to represent all the manuals - MSA and PPAP included. I don't remember a specific time period for gage R&R being stated anywhere in any of them. I remember getting hung up by a yearly re-PPAP requirement which included - yes - a gage R&R. Thus it was not a matter of QS or the MSA manual specifically stating: "Ye shall do a gage R&R on every gage every year..."

You have to look at this with respect to customer specific requirements, the MSA Manual, the PPAP manual, your company specific requirements and the gage its self. Again, to use an obvious example, what good will a yearly gage R&R do on an optical comparator in a lab environment? To repeat from above: "...Is it only used twice a year on 5 parts for 10 total measurements? Or is it used to take 100 measurements a day? How critical is the measurement? Is it used on a production line or is it used in a lab? How is it protected? What type of gage is it? For example, how often would you want a gage R&R on an optical comparator? Or laser mics? Or a steel rule?..."

If you have someone who really does know measurement as a system, it may be that that person could give a good reason for an R&R every 5 years or so. Maybe even 10.

As an off handed remark I said 9 years is rediculous, however I did what most tend to do (including some auditors) - over-categorize. Until I know the details of what the equipment is we are talking about, its use, etc., etc. I cannot say what is reasonable.

I will say that QS-9000 and it's accompanying MSA manual changed the face of calibration requirements and such. Even 10 years ago few companies did statistical studies like gage R&Rs. My learning curve was relatively steep. But then again, I began at a time when calibration was the concern - not statistical studies. Mil-Std-45662 was my first calibration 'bible' along with Mil-Std-120(?) for gages.

I thank John Adamek - a very early Cove Forums visitor - whom I argued with as the 'requirement' evolved from "Is your equipment calibrated? Let's see the certs..." to "Show me your statistical studies for the gage including it's uncertainty..." He brought me to understand (finally) the system aspect of measurement. I was stuck in the "Is your equipment calibrated?" mode and I also assumed some things. Being from a military equipment manufacturing background, and having been heavy into the sciences in college, I was reasonably knowledgeable about the importance of accuracy of measurement and test equipment. Mostly from college where I remember Dr. Schultz (freshman Chemistry 101) asking several of us to take a measurement of the same sample using the same scale (weight). He pointed out the effect of consistency in readings and how even looking at the 'needle' from different angles led to different readings. By the time I was through Organic Chemistry, I well understood the importance of the right measurement 'tool' for the job and how important consistency is. But - I was not an engineering student so we never looked at measurement in a manufacturing setting with the notable exception of spending a day in the Bubweiser labs in St. Louis (a class field trip...!) where we were shown "...what scientists do...".

I think what I was leading to here is when I hit consumer products I assumed companies had better qualified cal people than most did. In military manufacturing (at least at places like Cincinnati Electronics and Westinghouse) you didn't do charts and such for linearity, bias, etc., but the cal folks did know of these issues and (like in APQP today) the cal folks were involved early in every project to help determine the appropriate gages or test equipment. PCs brought calibration databases. Before that it was look at the cards. And by looking at the cards, if you know what you're doing, you can even see the equipment wear. The data told you - you didn't need to plot it to 'see' the trend.

But enough of that. If you want to read me making (at least partially) an *** of myself, read through http://elsmar.com/level2/cal_q1.html

And you have not said - or maybe I missed it. What type of instrument is your question about? All you have told us is that it is a gage. I would also want to hear their arguement on why they believe 9 years is the appropriate frequency for an R&R.

Also see http://elsmar.com/Forums/showthread.php?threadid=927

Marc.

Thank you once again for your input.

I apologise for not giving the complete info on the gauge. The gauge was in fact an external 0-25mm Micrometer and is being used to measure the diameter of wire.

As soon as I get a reply from the supplier I shall let you know their "feeble" excuse for this time gap. :)

To me it boils down to this being a mechanical gage and is subject to wear and such. If the gage is 9 years old and being used in a production setting (medium to high), I would cringe as you did. But again, listen to their whole story.

Hi,

Newbie here. I joined because I've been tasked as the MSA goto guy, and am trying to figure out some specifics about MSA. That's how I found this thread.

I must preface my comment by begging your forgiveness for my ignorance as a newbie. However, the nine-year interval since last MSA study does not seem to me to be rediculous [sic] as previously stated, as long as they can show that the tool has been regularly calibrated and checked against a known standard and not show a drifting in values. Am I off-base with this?

Thanks. I go off in search of the answers to my questions...

-benwah:bigwave:

> However, the nine-year interval since last MSA study does
> not seem to me to be rediculous [sic] as previously
> stated, as long as they can show that the tool has been
> regularly calibrated and checked against a known standard
> and not show a drifting in values.

Well, I tried to make the point that in RARE cases 9 years *might* be acceptable. I personally really can't think of an example. Can you? And if so, can you tell us why 9 years or more is an appropriate interval?

> rediculous [sic]

Sorry. Ridiculous. You may find other spellng errors here amongst the posts in the threads. Part of the medium and method.

Hi Marc,

I put my ideas forth more as an opinion that was open to correction. I, personally, would not have a problem with an MSA that was that old, provided that in-house verification records were available and complete, and anual calibration by an outside source were done. Good enough for me, but not sure if the rest of the Quality World agrees. I kind of expected someone to squash me and tell me that this would be unacceptable because...

Still not sure if that input of mine is worth a hoot! :)

As to the [sic] portion, I didn't mean to offend (I hope I did not!). I just saw the same spelling on a couple of the replies, and had to throw mine in, too (but wanted to make sure that people understood that I know the correct spelling!). ;) I understand that spelling is usually not the greatest on these types of forums (I've seen some REALLY bad spelling/grammer on another board I frequent), and try to mind my manners. I really meant no offense in this.

Best Regards,
-benwah

dear all,
i maybe wrong....but MSA tells us if that kind of equipment is suitable to measure this characteristic (with specific torelance) by these group of appraisers. and, if it is so, no matter how long was it studied; 9,10,11 yrs; it is ok...under the condition that tolerance is not changed or reduced..the equipment is under calibration and the appraisers are well trained.

:( any comments??

Originally posted by benwah

I put my ideas forth more as an opinion that was open to correction. I, personally, would not have a problem with an MSA that was that old, provided that in-house verification records were available and complete, and anual calibration by an outside source were done. Good enough for me, but not sure if the rest of the Quality World agrees. I kind of expected someone to squash me and tell me that this would be unacceptable because...

Still not sure if that input of mine is worth a hoot! :) Yes - your opinion and knowledge is worth much!As to the [sic] portion, I didn't mean to offend (I hope I did not!). I just saw the same spelling on a couple of the replies, and had to throw mine in, too (but wanted to make sure that people understood that I know the correct spelling!). ;) I understand that spelling is usually not the greatest on these types of forums (I've seen some REALLY bad spelling/grammer on another board I frequent), and try to mind my manners. I really meant no offense in this.No offense taken. I stopped using it ([sic]), except in rare cases, because on these 'board' systems people (myself included) don't always take the time to spell every word correctly. Not to mention I found many people do not know what [sic] means! I won't begin to address grammar or capitalization. I only mentioned it because I see it so rarely any more.

I don't disagree with you, I don't believe, on the R&R issue, in principle. I cited the optical comparaor in a lab because that might be an excample of where a yearly R&R would be of little value. But there are factors which can make 10 years a long time - some of which are not readily apparent.

One example was where a company 'down graded' it's personnel requirements for certain positions. The older employees the gauge R&R was done with produced a better R&R than the newer, less trained, lower paid, less disciplined employees. Totally unrelated to the instrument in question, the effect was significant.

It is for this reason that I believe each instrument has to be looked at on an individual basis as to wether and when an R&R is done.

> but MSA tells us if that kind of equipment is suitable to
> measure this characteristic (with specific torelance) by
> these group of appraisers. and, if it is so, no matter how
> long was it studied; 9,10,11 yrs; it is ok...under the
> condition that tolerance is not changed or reduced..the
> equipment is under calibration and

This is so, but the AIAG's MSA book is far from a bible and I know some automotive customers now *require* yearly MSAs.

I am more interested in the explaination of why and when an R&R is done on a specific guage than if it's done once a month, once a year or once in its life time. This is because I want to ensure the people understand what R&R and MSA are with respect to their processes and product(s).

I guess I'm like the dog holding the bone. How can one prove stability without monitoring the bias over the life of the gage?

Originally posted by Stuart Andrews

"Your statement about "the Auto industry via QS" stating yearly, I'm not able to find that in writing. Would you be able to point me in the right direction, so I can quote it correctly to our suppliers."This might be too late, and i'm not sure whether this is what u're looking for...

Section 4 'General Guidelines' 5th paragraph of MSA Reference Manual, p.9

'The objective of Phase 2 testing is to verify that a measurement system, ...., CONTINUES to have the appropiate statistical properties. ............GAUGE R&R is one form of Phase 2 testing...... Phase 2 testing is FREQUENTLY PERFORMED AS A ROUTINE PART OF THE FACILITY'S NORMAL CALIBRATION PROGRAM,.........................

please let me know

I'm pretty sure Chrysler, at least, requires them yearly as a customer requirement. So make sure whether there are, or are not, specific customer requirements.