Specify the options for Crossed Gage R&R Study

Stat > Quality Tools > Gage Study > Gage R&R Study (Crossed) > Options

Study variation

Enter a constant 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 constant by 2 for these calculations.

Process tolerance

Enter the specification limits or the tolerance range to compare the measurement system variation to customer specifications. When you enter a specification limit or the tolerance range, Minitab displays a %Tolerance column in a table and in the Components of Variation graph. The %Tolerance column shows the percentage of the tolerance taken up by the measurement system variation.

Enter at least one specification limit: Enter one or both of the specification limits for the measurements to compare measurement system variation to customer specifications.
Note
Minitab can calculate the probabilities of misclassifying product when you enter at least one of the individual specification limits.
- Lower spec: Enter the lower specification limit.
- Upper spec: Enter the upper specification limit.
Upper spec - Lower spec: Select this option if you have both an upper and a lower specification limit, and you do not want to calculate the probabilities of misclassifying product. Enter the difference between the specification limits. This is also known as the tolerance range.

Historical standard deviation

Enter a known value for the total variation, which is the part-to-part variation plus the measurement system variation. Use the drop down to specify whether to use the historical standard deviation to estimate the process variation or to use the parts in the study to estimate the process variation.

When you select Use parts in the study to estimate process variation, Minitab displays a %Process column in a table and in 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 alpha value (also called significance level) that is used to remove the interaction term from the model. This option is only available with the ANOVA option (default) for Method of Analysis.

Usually, a significance level of 0.05 works well. A significance level of 0.05 indicates a 5% risk of concluding that the variability from the interaction term is significant when it is not.

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

Display probabilities of misclassification

If you have specified at least one specification or entered the tolerance range under Process tolerance, select this option to display the probabilities of misclassification. For more information go to All statistics and graphs and click "Probabilities of misclassification". This option is only available with the ANOVA option (default) for Method of Analysis.

If you enter a historical value, Minitab uses the value that you enter instead of the estimated standard deviation, to calculate the probabilities of misclassification.

Do not display percent contribution

Specify whether to display percent contribution.

Do not display percent study variation

Specify whether to display percent study variation.

Draw graphs on separate graphs, one graph per page

Display each graph separately. By default, Minitab displays the 6 graphs together.

Title

You can enter a custom title for the gage study.