MKS Inc., produces meter sticks that have a target length of 100 centimeters with upper and lower specification limits of 100.05 and 99.95 centimeters respectively. Their existing process produces meter sticks with an average length of 100.00 centimeters and a standard deviation of 0.015 centimeters. What is their current process capability index?
A) 0.44
B) 0.83
C) 1.11
D) 1.26

Question

Quizplus · Accepted Answer

The process capability index (Cpk) is calculated as the minimum of (USL - mean)/(3*standard deviation) and (mean - LSL)/(3*standard deviation). Here, Cpk = min((100.05-100.00)/(3*0.015), (100.00-99.95)/(3*0.015)) = min(1.11, 1.11) = 1.11.

MKS Inc, Produces Meter Sticks That Have a Target Length of of 100