Centering Values for Short-Term Statistics
main topic

Minitab considers three possibilities for centering values in calculating short-term statistics:

· Target, when one is specified.

· Midpoint of the specification range, (USL + LSL)/2, when both specification limits are given but no target value.

· Process mean, when only one specification limit is given and no target value.

Note	The target value does not impact the long-term Z calculations. The long-term Z-values center on the mean of the data.