Managing for Quality and Performance Excellence 9th Edition by James Evans,William Lindsay

Exercise 10

Nanospark Electronics manufactures 100,000 circuit boards per month. A random sample of 1,000 boards is inspected every week for three characteristics. During a recent week, three defects were found for one characteristic, and one defect each was found for the other two characteristics. If these inspections produced defect counts that were representative of the population, what is the overall sigma level for this process? What is the sigma level for the characteristic that showed three defects?