A process that produces computer chips has a mean of .04 defective chip and a standard deviation of .003 chip. The allowable variation is from .03 to .05 defective. a. Compute the capability index for the process. b. Is the process capable?

A. 1.111

B. The process is not capable

Explanation:

Part A

Capacity index help to determine the performance of a process and how it could perform in the future. A capacity index of above 1.33 means that the process is capable but a capacity index below 1.33 means that the process is not capable. The capacity index can be calculated using equation 1;

From the mean  which is 0.5, it can be determined that the process is a centered process.

For centered process, the mean = 0.5 x (Upper s. - Lower S.) = 0.5 x 0,02 = 0.04

so the capacity index for centered mean will be used

................................................1

Given standard deviation = 0.003

upper specification = 0.05

lower specification = 0.03

Therefore the capacity index of the process is 1.111

Part B

The capacity index of the process is 1.111 and it is less than 1.33, this means that the process is not capable.