Control Charts and Purchasing

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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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Comments (2)

  • AnonymousOctober 7, 2015 Reply

    Interesting post, thank you.I'm interested to know why you would use an X-mR chart here and not a p chart?Thank you

  • billOctober 8, 2015 Reply

    Thanks for the comment. The p control chart has to satisfy four conditions to be used. These are given in the publication at this link. For example, one is that the probability of being a stock out, for example, has to be the same for all products That is not the case – faster moving items probably have a higher probability of being stocked out – or a very slow moving item also. So, if the conditions are not met, you can’t use the p control chart.

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