Question

A process produces a certain part with a mean diameter of 2 inches and a standard deviation of 0.05 inches. The lower and upper engineering specification limits are 1.6 inches and 3.5 inches. What is the Cp (measure of potential capability)?

Answer 1

The value of Cp (measure of potential capability) is 6.33.

Explanation:

Given information: Process average = 2 inches, process standard deviation = 0.05 inches, lower engineering specification limit = 1.6 inches and upper engineering specification limit =3.5 inches.

The formula for Cp (measure of potential capability) is

`CP=(USL-LSL)/(6\sigma)`

Where, USL is upper specification limit, LSL is specification limit, σ is process standard deviation.

Substitute USL=3.5, LSL=1.6 and σ=0.05 in the above formula.

`CP=(3.5-1.6)/(6(0.05))`

`CP=(1.9)/(0.3)`

`CP=6.3333`

`CP\approx 6.33`

Therefore the value of Cp (measure of potential capability) is 6.33.