The Importance of the Operator by Part Control Chart in Gage R&R Studies

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Thanks so much for reading our publication. We hope you find it informative and useful. Happy charting and may the data always support your position.


Dr. Bill McNeese
BPI Consulting, LLC

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Measurement Systems Analysis/Gage R&R

Comments (4)

  • Tom HelmOctober 19, 2023 Reply

    Hi Bill – I posted this is a really old post, so i am going to repost it here since I think it may apply better to this article. Apologies for the redundancy:

    I am trying to figure out what gauge studies would tell me the most information I need to know. I develop automated inline inspection systems (machine vision based metrology), so they only have 1 operator (the system itself) and never get to remeasure the parts that just passed by them (i.e., no true repeatability).

    I can see utility in doing some prove out of the system by refeeding parts to capture repeatability or consistency, as this could show clear variation in how parts are presented to the vision system (i.e., fixturing or lighting). However, I want to do a study that most adequately assesses how the system behaves when it is being used as intended — only one operator and no remeasurement opportunities.

    Can you assist?

  • billOctober 20, 2023 Reply

    I see value in refeeding parts that represent the variaiton in your process. You can do the basic GageR&R study that way and find the meausrement errror, then compare that to the historical variation in the porcess. You may only have one operator but i assume they can be different over time. So, multiple parts and multiple operators.


  • Tom HelmOctober 24, 2023 Reply

    Hi there — the system itself is the operator. There is no human interaction with the measurement process since it is all done inline automatically. How do we simulate multiple operators in that case? Can we?

    And if we cannot refeed parts easily, or at all, is there a better way of assessing measurement variation relative to the process variation? I wanted to trial a nested GR&R or a destructive GR&R, but those also require multiple operators. Not sure how I can rationalize multiple operators without it being arbitrary.

  • billOctober 27, 2023 Reply

    Send me an email and we can chat further about this. [email protected]

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