Ravi's Blogs Measurement and Sampling Errors

Ravi Khare submitted a new resource:

Measurement and Sampling Errors - Errors in Quality assessment and their impact

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According to this AIAG blue book section F9 MSA studies are not required where standardized tests are used, however it is still important for the organization to understand the measurement component of variation.

We are TIER 1 supplier to the OEMs. We supply bulk fluids and often we do 100% inspection of incoming, in-process and final product. During the TS audits we struggle to convince the auditor that our MSA is based on the round robin samples analyzed by 100 participating laboratories. Our performance is based on the Z scores. The precision is traceable to ASTM R & R. Is our method adequate or there is a better one? Thank you.

 

Honestly, I don't know the answer to your question.

Adequacy in my opinion is a threshold perspective. It will be based on whether your customer feels confident about the quality you will supply, given the measurement characterization method you follow.

More thoughts on this from forum contributors here will help us learn about better methods that may exist.

 

Multiple samples of different product family are dispatched as “blind samples to multiple laboratories around the world. It is tested by different operators multiple times. Evaluation of results is based on z-score concept (ISO/REMCO N263). The participants try to be within the +/- 2Z to score a 100%. Any score outside that band in a bell curve needs to be investigated and corrected using the corrective action method. I read an article by Wheeler (I got it from Elsmar Cove that is similar to this method. This is documented clearly in our lab scope for the auditors to understand.

 

Check these out: When is GRR (Gage R&R) required? AIAG MSA Manual Version 4 and Difference between Gage R&R and Round Robin testing