## Quality Control in Practice

The problem in applying this result in quality control is that K is unknown. Therefore, in practice the following decision rule as to whether K < R or not is followed. Given a particular number r < n, to be determined at the end of this subsection, assume that the set of N bulbs meets the minimum quality requirement K < R if the number k of defective bulbs in the sample is less than or equal to r. Then the set A(r) = {0, 1,…, r} corresponds to the assumption that the set of N bulbs meets the minimum quality requirement K < R, hereafter indicated by “accept,” with probability

r

P(A(r)) = £ P({k}) = pr(n, K), (1.12)

k=0

say, whereas its complement A(r) = {r + 1n} corresponds to the assumption that this set of N bulbs does not meet this quality requirement, hereafter indicated by “reject...

Read More