Gauge R/R V %tolerance

%Tolerance in Minitab is what people often call the precision-to-tolerance ratio. That is, the percentage of the tolerance taken up by the measurement error. In your case, the results are telling you that the measurement error is taking up 22.29% of your total tolerance of 0.06mm (assuming you put everything into Minitab correctly).

I’m not sure what you mean by “the study has failed”. Is the customer saying that your gauge is inadequate because the P/T is > 20% or is there some suggestion that the GR&R study as a whole has “failed” because P/T is > 20%? If it is the latter, I don’t understand that at all. A 20% P/T is very typical. It is no indication of a flawed study.

In your case the 22.29% P/T ratio is on the high side regarding gauge adequacy, especially if you are expecting to get to a high sigma level in your process, but guidelines for P/T are usually set at < 30% with a k of 5.15 like you have. I would not think that this P/T value would indicate an inadequate gauge based on that measure alone.

Overall, with your P/T of 22.29% and your GR&R of 27.96% your process is running at a capability (Cp) of about 1. This corresponds to a sigma level of about 3. Decent, but not great.

You may want to look into a paper by a colleague of mine that does a great job of explaining P/T and GR&R together in a two-dimensional analysis. It may help you get a better understanding.

White, T. Kevin, and Connie M. Borror. “Two-dimensional Guidelines for Measurement System Indices.” Qual. Reliab. Engng. Int. 27.4 (2011): 479-87. Print.