You can have Minitab estimate the parameters of the nonnormal distribution used for the capability analysis or you can choose to enter some or all of the parameters below.
For more information on the shape, scale, or threshold of a distribution, go to Capability statistics for Nonnormal Capability Sixpack and click the parameter that you want to learn more about.
Use unbiasing constants in the estimate of the within-subgroup standard deviation. This option applies to the Sbar, pooled standard deviation, and square root of MSSD methods.
Unbiasing constants reduce the bias that can occur when a parameter is estimated from a small number of observations. As the number of observations increases, unbiasing constants have less effect on the calculated results. Often, the choice to use unbiasing constants depends on company policy or industry standards.
Enter the number of observations used to calculate the moving range. The length must be ≤ 100. The default length is 2 because consecutive values have the greatest chance of being alike.