Specifications and Measurement Error

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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 (5)

  • Stephen PuryearMay 31, 2016 Reply

    Hi, BillThank you once again for generously providing this very valuable objective viewpoint.  I know that it is valuable because I work in the US pharma sector and I know that it is quite averse to this sort of analysis. Also,  I see daily examples of the tremendous waste caused when subjective methods are used in it's place.  In pharma, measurement capability and uncertainty analysis is reserved strictly for the metrology associated with maintaining calibration standards.  Many years ago, the Barr Decision pointed out the pitfalls that follow along behind attempts to re-measure a "near OOT" quanitity in the hopes that subsequent values will be in tolerance. Your examples point out exactly the dangers in doing this wihout a comprensive plan or the kind of understanding that could easily result from reading and understanding these excellent articles.Thanks again, this is really good stuff!Stephen Puryear

  • Choi Fock CheongJune 1, 2016 Reply

    Dear Bill,We are unable to download the article in pdf reader format as per your addressed link. Kindly assist.Thank you.Rgds, Choi  

    • billJune 1, 2016 Reply

      When the reader comes up, there are a list of symbols on the left-hand side.  The fourth one down has "PDF".  Select that option.  Then select "Pages" so all pages will be downloaded as pdf.  Then select Save.  e-mail if you still have problems ([email protected])

  • TomaszAugust 18, 2022 Reply

    Hey Bill,Thx for great material. Can you double check comment under (for) figure 3, in particular:”As long as there are no out of control points, this moving range is consistent (in statistical control). This is true for the chart in Figure 3″We have one point out of the limit, retest item 8, mR value 1.3, which means, measurement system is not stable.

    • billAugust 21, 2022 Reply

      Yes you are correct.  There is one out of control point in the chart.  The comment is not correct.  However, it does not make a big difference in the calculations.  

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