In part one of this series, I looked at how adequate a sampling of 10 parts is for a gauge repeatability and reproducibility (GR&R) study and provided some advice based on the results.

Now I want to turn my attention to the other two factors in the standard gage (or gauge, if you prefer) experiment: three operators and two replicates. Specifically, what if instead of increasing the number of parts in the experiment (my previous post demonstrated you would need an unfeasible increase in parts), you increased the number of operators or number of replicates?

In this study, we’re only interested in the effect on our estimate of overall gauge variation. Obviously, increasing operators would give you a better estimate of the operator term and reproducibility, and increasing replicates would get you a better estimate of repeatability. But I want to look at the overall effect on your assessment of the measurement system.

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