Interpreting Operator-Part Interaction In Gage Repeatability And Reproducibility Studies

Measurement has been an important activity for centuries. The advent of Six Sigma initiatives has increased the assessment of measurement repeatability and reproducibility using Gage R&R studies. It is common practice that, when the operator-part interaction in Gage R&R studies is statistically significant, the associated variance component is used in estimating the test method reproducibility. In this article it is shown that the Operator-Part interaction may be due to systematic behavior of one or more operators thereby unnecessarily increasing the test method reproducibility variance. Several examples are included to demonstrate how the analysis is performed and how the results can be interpreted.