The specifications for a product are 6 mm ±0.1 mm.The process is known to operate at a mean of 6.05 mm with a standard deviation of 0.01 mm.What is the Cpkfor this process?
A) 3.33
B) 1.67
C) 5.00
D) 2.50
E) None of the choices are correct.

Question

Quizplus · Accepted Answer

Cpk is calculated as the minimum of (USL - mean)/(3*standard deviation) and (mean - LSL)/(3*standard deviation). Here, USL = 6.1, LSL = 5.9, mean = 6.05, and standard deviation = 0.01. Cpk = min((6.1-6.05)/(3*0.01), (6.05-5.9)/(3*0.01)) = min(1.67, 5) = 1.67.

The Specifications for a Product Are 6 Mm ±0