Methods and formulas for expected overall performance in Nonnormal Capability Analysis

The expected number of parts per million that have measurements less than the lower specification limit is calculated as follows:

PPM < LSL = 1,000,000 * F(LSL)

The expected number of parts per million that have measurements greater than the upper specification limit is calculated as follows:

PPM > USL = 1,000,000 * (1 – F(USL))

The expected number of parts per million that are outside of the specification limits is calculated as follows:

PPM Total (Exp. Overall) = PPM < LSL (Exp. Overall) + PPM > USL(Exp. Overall)

PPM Total (Exp. Overall) = [1,000,000 * F(LSL)]+ [1,000,000 * (1 – F(USL))]