How to resolve discrepancies in Level 3 PPAP supplier dimensional reports?

Nath2892

Starting to get Involved
Hello everyone. Our supplier sends dimensional report as part of initial level submission PPAP, Level 3. In order to verify dimensional report, we perform inspection on the same PPAP sample parts that supplier used for dimensional report. I'm all new to automotive industry and I would like to know what steps needs to be followed if you find any discrepancies. For eg., A critical characteristic in supplier dimensional report is within spec BUT is out of spec during our internal testing (Sample Size is 20 in both cases). How can these type of situations be resolved? What if the supplier "claims" they re-measured the particular feature and didn't find any out of spec dimension?
 

eule del ayre

Involved In Discussions
Measure the sample parts, and tabulate the differences of your measurements from your side and your supplier. Base on my experience, in your situation, i think it's on the appraiser side.
 

Golfman25

Trusted Information Resource
Depending on the part and dimension, make sure you are both measuring the same way. You'll get different results if say they measure a dia. on a CMM and you check it with a caliper.

We had a situation where a "Quality Engineer" was ratcheting down with a micrometer on a thin walled part, actually collapsing the part, and claiming they where out of spec. It was frustrating. Good luck.
 

Nath2892

Starting to get Involved
Depending on the part and dimension, make sure you are both measuring the same way. You'll get different results if say they measure a dia. on a CMM and you check it with a caliper.

We had a situation where a "Quality Engineer" was ratcheting down with a micrometer on a thin walled part, actually collapsing the part, and claiming they where out of spec. It was frustrating. Good luck.

Thank you for your reply. Yes. Inspection method is different in both cases. Supplier is using OMM and we used CMM to measure the dimensions. I'm afraid our facility doesn't have OMM to make sure we are measuring the same way but I'll try. Thanks for your advice.
 

Nath2892

Starting to get Involved
Measure the sample parts, and tabulate the differences of your measurements from your side and your supplier. Base on my experience, in your situation, i think it's on the appraiser side.

Thank you for your reply. We measured the sample parts and I tabulated the differences i observed between our internal inspection report and supplier dimensional report (Clearly mentioning which dimensions were within spec in dim report but out of spec at our facility). When i asked Supplier to remeasure the parts again, they got the similar results they had in dimensional report (All within spec).
 

Jim Wynne

Leader
Admin
Thank you for your reply. We measured the sample parts and I tabulated the differences i observed between our internal inspection report and supplier dimensional report (Clearly mentioning which dimensions were within spec in dim report but out of spec at our facility). When i asked Supplier to remeasure the parts again, they got the similar results they had in dimensional report (All within spec).
How much of a difference are we talking about? You say it's a critical characteristic, so if it's out of spec, functionality or safety or something critical should be affected. Is this the case?
 

Nath2892

Starting to get Involved
How much of a difference are we talking about? You say it's a critical characteristic, so if it's out of spec, functionality or safety or something critical should be affected. Is this the case?

Hello Jim. Yes. It's functional. It's not just a single critical dimensions. There are atleast 2-3 functional dimensions which are out of spec by 0.02-0.05mm.
 

Jim Wynne

Leader
Admin
Hello Jim. Yes. It's functional. It's not just a single critical dimensions. There are atleast 2-3 functional dimensions which are out of spec by 0.02-0.05mm.
Can you describe the features in question? What was the actual specification for the dimension that's out by 0.02mm (<.001")?
 

Proud Liberal

Quite Involved in Discussions
You also need to define EXACTLY how each methodology is collecting and evaluating the feature(s) in question. Even using the exact same piece of equipment (ie: CMM), results can vary greatly by how it's programmed. My experience has seen many instances where the design engineer and/or the metrologist don't understand what is required from a measurement to make it provide accurate information to make good decisions. Sometimes (or even more often than that), the print requirement isn't was is truly necessary for good decisions.

But at this point in the process, you'll need to focus on aligning the methodologies and any need to correct print corrections will probably have to wait (that just the politics of doing PPAP).
 

eule del ayre

Involved In Discussions
Thank you for your reply. We measured the sample parts and I tabulated the differences i observed between our internal inspection report and supplier dimensional report (Clearly mentioning which dimensions were within spec in dim report but out of spec at our facility). When i asked Supplier to remeasure the parts again, they got the similar results they had in dimensional report (All within spec).


Sir Nath2892, conventional way of measuring or electronic?
 
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