MSA on Part Specific Attribute Fixtures

[jackerman64]

We do MSA studies by gage "type".
For example: One R&R for all 6" calipers, One R&R for all 12" calipers etc
In my past experience (24 years), an R&R has been performed on each individual custom check fixture.
However, in my past, the parts were very different from each other and the custom fixtures were a combination of attribute and variable measurements.

Our QM is challenging that although the various check fixtures we have are part specific, they are still 1 gage type because they all function the same and measure the same type of part. For example, a LH wheel well splash guard and a RH wheel well splash guard and also for various vehicle models)
They are all attribute fixtures. A part is laid on the base and and then clamped. Stab pins ensure proper position. A profile site line is visually checked around the perimeter of the part and various plugs are used to check hole sizes.

Would you consider this one gage type?
In my past I would have said no but I'm trying to be open and explore the possibility that perhaps my trainer misinterpreted the requirement.

Your thoughts?

 

[Ninja]

My two cents...not sure there is a "right" answer.

I would remove the concept of "gage type" from your thinking...you have a TEST METHOD, not a gage.

When running a GRR, I would test the same characteristic, "A profile site line is visually checked around the perimeter of the part" using the various calibrated fixtures used in that test method(s). Same with plugs.

You use a set of plugs to measure hole size. That's a test method you are verifying via GRR. Right or left is immaterial.

You use a set of fixtures to measure (a profile shape?). That's a test method you are verifying by GRR. right or left is immaterial.

If you are looking at ensuring your TEST METHOD is adequate, many of your finer distinctions disappear...and life gets easier for all.

 

[howste]

My two cents...not sure there is a "right" answer.

I would remove the concept of "gage type" from your thinking...you have a TEST METHOD, not a gage.

Assuming we're talking about IATF 16949 here, this is the relevant text of the standard:

Statistical studies shall be conducted to analyze the variation present in the results of each type of inspection, measurement, and test equipment system identified in the control plan.

Since the standard uses the word "type" of system it's hard to remove that word from our thinking in this case. Is a type of inspection/measurement/test system the same as a test method? Maybe. I would at least think that right-hand and left-hand fixtures that mirror each other would be the same type.