QUESTION: I AM BEING ASKED BY A CUSTOMER TO SUBMIT STABILITY, LINEARITY & BIAS STUDIES ALONG WITH THE GR&R FOR EACH PPAP I SUBMIT. AM I MISINTEREPTING THE STANDARD OR IS THE CUSTOMER BEING UNREASONABLE. YES, THE CUSTOMER IS ALWAYS RIGHT BUT CAN ALSO BE UNREASONABLE. WOULD LIKE YOUR COMMENTS ON HOW YOU INTERPRET THIS.
Boy I remember this same situation during our initial QS certification audit - we received an "Observation" from the third party auditors saying that we needed to have a five part MSA. Our response was, "No" our QM stated we needed to conduct the appropriate statistical studies to analyze variation "(e.g., bias, linearity, stability, repeatability and reproductibility studies, etc.)" and we're evaluating that need and complying based on each of the pertinent technologies' parameters. Surveillance audit - they came back again and said "we really meant it the first time when we told you that you needed to have a 5 part MSA." Our response
bascially came down to "what don't you understand about the meaning of e.g.", they were not amused. By this time the third party auditors were writing up sister Divisions throughout the entire Sector for the same thing, since the writing was on the wall we finally just caved. We adopted the attitude that following a 5 part MSA was just rounding out the characterization process and the right thing to do - our Ops Manager was a master at looking for the positive spin and selling it. However, it was very galling to have someone reinterpret and apply what we felt were clear instructions in our QM.
The bottom line is the requirement has evolved. Initially the question was whether your M&TE was calibrated. Now it is do you understand measurement systems and do you demonstrate this understanding through out PPAP including decisions on what to use to measure what on through uncertainty. It was 1996 or 1997 when things started getting 'more to the point' so to speak. I have had heated 'discussions' with folks in the past over this issue. I can see its merits.