Question

The wall street journal reported on February 15 2000, that about 750,000 airplanese components are manufactured , machined or assembled for Boeing & co by workers from the Seattle lighthouse for the blind. A Boeing spokeswomen noted that the parts have exceptionally low rejection rate of one per thousand. At what sigma level is the process operating, considering an off-entering of 1.25 sigma can be detected

Answer 1

There is no indication of how many opportunities for defects there are per component, so we will have to assume that the defect rate is 1 per 1000 units produced. Therefore, only 750 defective items (0.001 X 750,000) were produced. To calculate dpmo, we see:

dpmo = (1/1000) X 1,000,000 = 1000, which is slightly better than 4.5 sigma

with off centering of 1.5 sigma