Parameters:
(1) percent allowable/expected defects in the run
(2) number of items in a random sampling from the run
(3) total number of rejected items in the random sample before rejecting a run
The probability uses a cumulative binomial distribution, since there is a probability of rejecting the run based on 0, 1, 2,....,(total number of rejected items).
probability of passing a production run based on the cumulative binomial distribution =
= (CUMULATIVE SUM from 0 to (total number of rejects) for the binomial distribution with N = number of random samples; x = total number of rejected items; p = percent allowable errors; q = 1 - p))
In Excel, this would be expressed as:
probability of accepting a production run =
= BINOMDIST(total number rejects, number of random samples, percent allowable defects, TRUE)
where:
• TRUE indicates cumulative binomial distribution from 0 to total number of rejects. FALSE would be the binomial distribution only at that value).