Risk Analysis for Proficiency Testing

[jbastin]

Can anybody provide any insights about the risk analysis for PT/ILC plan for a dimensional measurement laboratory as per the below section in AR 2259?

"1.1.2. The laboratory shall maintain a documented plan that ensures participation for the current year
and at least the next three years covering a representative sampling of activities within each major field identified in the scope of accreditation.

a. The laboratory shall evaluate the risk of the measurement associated with the scope of
accreditation and incorporate that risk analysis as part of the PT plan."

 

[Tidge]

When I worked at a materials metrology lab, we subscribed/participated in a round-robin service where we tested some fraction of 'control samples' along with other laboratories (our competitors, I assume). After each round, the subscribers were sent the results of all labs (anonymized) and we were shown were our results fell on the distribution of all results.

From memory: We did not participate in a similar round-robin service for physical performance testing; the performance tests were (mostly) destructive and were performed according to (mostly) ASTM standards. We had membership on the relevant ASTM committees and our adherence to the test methods were covered by external accreditation audits. There was some level of internal auditing, but from memory this was slightly more ad hoc than I would have preferred: generally it was the case that when we'd observe failures we would retest, but this was a business decision (to not upset clients) instead of some formal method of addressing a (potentially) "false failure" error. In the years at that lab, I can't ever recall a second round of performance testing on a product that originally passed.