Specify the default settings for gage R&R studies

File > Options > Control Charts and Quality Tools > Gage R&R Study

Specify the default settings for gage R&R studies. The changes you make to the defaults remain until you change them again, even after you exit Minitab.

Study variation

Specify the default number to multiply by the standard deviation to estimate the variation in the measurements. The default multiplier is 6, which is the number of standard deviations that is needed to include 99.73% of your measurements.

Note

If you provide only one specification, and you want to include 99.73% of your measurements, you do not need to change the 6 to a 3. Minitab divides the number by 2 for these calculations.

If historical standard deviation is entered

Use historical standard deviation to estimate process variation: Select to use the historical standard deviation when a known value for the total variation is entered in the dialog box.
Use parts in the study to estimate process variation: Select to use the measurement data in the worksheet to estimate the total process variation even when a historical standard deviation is entered in the dialog box. When you select this option, Minitab displays a %Process column in the output and on the Components of Variation graph. The %Process column shows the percentage of process standard deviation taken up by each variance component.

Alpha to remove interaction term

Enter the default significance level that Minitab uses to remove the interaction term from the model. Minitab uses this option only with the ANOVA method. The default value is 0.05. Minitab also uses this value for Evaluate Measurement Process (EMP Crossed).

Use a higher significance level, such as 0.10 or 0.25, if you want to be more likely to keep the interaction in the model. Use a lower significance level, such as 0.01, to be less likely to keep the interaction in the model.