Calculations for the specification limits for Calculate Gap Pools

Element lower specification limits

If not specified, Minitab calculates using long-term element Z.Bench and long-term element standard deviation as shown.

Element nominal values

If not specified, Minitab uses the mean.

Nominal = T_i

Element upper specification limits

If not specified, Minitab calculates using long-term element Z.Bench and long-term element standard deviation as shown.

Long-term Z score of the element lower specification

Long-term Z score of the element upper specification

Defects parts per million associated with the lower specification

PPM.LSL_i = Φ(–Z.LSL) * 10⁶

Defects parts per million associated with the upper specification

PPM.USL_i = Φ(–Z.USL) * 10⁶

Defects parts per million associated with the specification limits

PPM.Total_i = PPM.LSL_i + PPM.USL_i

First time yield in percentage of the i^th element

Defects per unit