Generic or Specific Gauge R&R on Standard Equipment (ie.: Micrometer)

[amilboa265]

We have conducted generic R&R studies on standard equipment ie Micrometer. A customer has requested that a R&R study be conducted using the same equipment (ie micrometer already conducted) but on there specific product. I do not see that this is a requirement in the MSA 4th edition manual, unless anyone else can correct me??

 

[NumberCruncher]

Hi amilboa265

There is nothing in the MSA manual that requires you to use a specific customer's product.

The MSA study takes into account the variabilty in the person, the gauge and the part.

Let's say that you make several different product lines for different customers. Call those lines A and B. Then suppose that the process variation in line A is a bit bigger than line B.

Assumng that you have selected a representative range of parts from line A, your R&R results would look ok.

If you select a representative range of parts from line B, which has a lower process variation than line A, your R&R results may not look quite as good.

In this case, your customer may have a point.

If, on the other hand, you are making a standard product, and your customer simply buys from a common stock of goods, then personally, I fail to see the point of carrying out a second study.

How was the generic R&R study done?

The other problem is simply one politics. It's what your customer wants!

NC

 

[Jim Wynne]

We have conducted generic R&R studies on standard equipment ie Micrometer. A customer has requested that a R&R study be conducted using the same equipment (ie micrometer already conducted) but on there specific product. I do not see that this is a requirement in the MSA 4th edition manual, unless anyone else can correct me??

Hi amilboa265

There is nothing in the MSA manual that requires you to use a specific customer's product.

The MSA study takes into account the variabilty in the person, the gauge and the part.

Let's say that you make several different product lines for different customers. Call those lines A and B. Then suppose that the process variation in line A is a bit bigger than line B.

Assumng that you have selected a representative range of parts from line A, your R&R results would look ok.

If you select a representative range of parts from line B, which has a lower process variation than line A, your R&R results may not look quite as good.

In this case, your customer may have a point.

If, on the other hand, you are making a standard product, and your customer simply buys from a common stock of goods, then personally, I fail to see the point of carrying out a second study.

How was the generic R&R study done?

The other problem is simply one politics. It's what your customer wants!

NC

If you do a "generic" gage study, on gage blocks for example, what you're showing in essence is that the measurement system is appropriate (or not) for measuring gage blocks. It's perfectly reasonable for a customer to expect GR&R to be done on the part feature(s) of interest.

There is no reason, however, that products and their characteristics shouldn't be arranged in "families" when it's sensible to do so. If the characteristics to be measured are sufficiently similar to make additional gage studies needlessly redundant, there shouldn't be a need to do additional studies. This is a matter of rational judgment and customer acquiescence, not something to be done to avoid useful work. Sometimes customers won't listen to reason and needless work has to be done, but if your rationale for GR&R economy is sound, you should at least discuss it with the customer.

 

[amilboa265]

Thanks NC. We make reasonably standard product, all customer parts are bespoke, but variations on our core manufacturing capability, using micrometers and verniers to measure lengths and diameters.

The original GRR were 3 people, 10 parts, 3 repeats to get results for a type of micrometer, which we use across the company. This has always been accepted by all customers. Whilst i appreciate the political aspect, I do not want to set a precedent with this request, as it would probably not be sustainable to continually carry out GRR for each new part.

I really wanted to make sure that I hadn't missed anything in the MSA book. Thanks very much for your reply.

 

[Jim Wynne]

Thanks NC. We make reasonably standard product, all customer parts are bespoke, but variations on our core manufacturing capability, using micrometers and verniers to measure lengths and diameters.

The original GRR were 3 people, 10 parts, 3 repeats to get results for a type of micrometer, which we use across the company. This has always been accepted by all customers. Whilst i appreciate the political aspect, I do not want to set a precedent with this request, as it would probably not be sustainable to continually carry out GRR for each new part.

I really wanted to make sure that I hadn't missed anything in the MSA book. Thanks very much for your reply.

I don't have the 4th Edition MSA manual handy, but I can tell you that nearly all of it is based on the assumption that R&R (and other analyses) will be done using parts and not standards. I don't know what you mean when you refer to "generic" studies, but if you mean that the studies weren't done using parts representative of your products, I wouldn't be surprised if a customer rejected them.

 

[amilboa265]

By generic i meant that we have used one of our parts in the GRR study. Our products are all variations on a theme, so whilst the GRR study is not specific to one customer, the parts should be representative of what we supply to that customer. As i said, all our parts are bespoke to customer drawings, but they are all variations of a theme.

 

[Jim Wynne]

By generic i meant that we have used one of our parts in the GRR study. Our products are all variations on a theme, so whilst the GRR study is not specific to one customer, the parts should be representative of what we supply to that customer. As i said, all our parts are bespoke to customer drawings, but they are all variations of a theme.

Again, I don't have the 4th Edition MSA manual handy, but it does account for doing "families" of gages. Perhaps someone here can provide the direct reference.

 

[Golfman25]

I think Jim's first point is right on. If there is justification of similarly situation parts, i.e; families, then seperate studies are a waste (and don't we all want to reduce waste?). However, it might be easier to do the study than convince your customer. Unfortunately today, customers are more concerned that all the "boxes match" rather than some common sense thinking. Good luck.

 

[NumberCruncher]

Again, I don't have the 4th Edition MSA manual handy, but it does account for doing "families" of gages. Perhaps someone here can provide the direct reference.

Hi Jim

I have searched through the MSA manual, and whilst I can't say that I have read every single word, I can't find any reference to families of gauges. Miner mentions them in one of his blogs.

Free - Miner's MSA "Blog" Series

Other than that, I can only find a document on the internet, "Ford Motor Company Customer-Specific Requirements For Use With ISO/TS 16949:2002

http: //www .iaob .org /pdfs/FordspecTS2nd_December 2007.pdf - DEAD 404 LINK UNLINKED

Page 18 states

"4.35
Measurement systems analysis (ISO/TS 16949:2002 cl. 7.6.1)

All gauges used for checking Ford components/parts per the control plan shall have a gauge R&R performed in accordance with the appropriate methods described by the latest AIAG Measurement Systems Analysis Manual (MSA) to determine measurement capability.

Any measurement equipment not meeting the specifications stipulated in the MSA must be approved by STA.

Use of family gauge studies per the MSA is permissible and must be approved by STA "

Where STA is

"Supplier Technical Assistance – Ford Motor Company's team dedicated to assist in the development of supplier processes."

I don't know if this is a unique Ford concession, or if it applies more widely. Perhaps Miner could enlighten us?

NC

 

[Jim Wynne]

Hi Jim

I have searched through the MSA manual, and whilst I can't say that I have read every single word, I can't find any reference to families of gauges. Miner mentions them in one of his blogs.

Free - Miner's MSA "Blog" Series

Other than that, I can only find a document on the internet, "Ford Motor Company Customer-Specific Requirements For Use With ISO/TS 16949:2002

http ://www .iaob. org/pdfs/FordspecTS2nd_December 2007.pdf - DEAD 404 LINK UNLINKED

Page 18 states

"4.35
Measurement systems analysis (ISO/TS 16949:2002 cl. 7.6.1)

All gauges used for checking Ford components/parts per the control plan shall have a gauge R&R performed in accordance with the appropriate methods described by the latest AIAG Measurement Systems Analysis Manual (MSA) to determine measurement capability.

Any measurement equipment not meeting the specifications stipulated in the MSA must be approved by STA.

Use of family gauge studies per the MSA is permissible and must be approved by STA "

Where STA is

"Supplier Technical Assistance – Ford Motor Company's team dedicated to assist in the development of supplier processes."

I don't know if this is a unique Ford concession, or if it applies more widely. Perhaps Miner could enlighten us?

NC

Where the Ford thing says "Use of family gauge studies per the MSA..." it most likely means per the MSA manual, but because I don't have the 4th edition manual I can't confirm it. Thanks for looking. In any event, family GR&R is common practice and should be done where appropriate and where customers agree to it.