A metal-cutting operation has a target value of 20 and consistently averages 19.8 with a standard deviation of 0.5. The design engineers have established an upper specification limit of 22 and a lower specification limit of 18. What is the process capability index?
A) 1.20
B) 1.33
C) 1.46
D) 1.66

Question

Quizplus · Accepted Answer

The process capability index (Cpk) is a measure of how well a process meets specifications. It is calculated as the minimum of the upper and lower specification limits minus the process mean, divided by three times the process standard deviation. In this case, the Cpk is calculated as (22 - 19.8) / (3 * 0.5) = 1.20.

A Metal-Cutting Operation Has a Target Value of 20 and Consistently