Work out acceptance number (aql) instantly with clear inputs, formula shown and shareable results.
The operating characteristic curve of a single sampling plan gives the probability of accepting a lot of given quality: the Poisson sum of P(k defects) for k up to the acceptance number, with mean sample size x defect rate. A plan is defined by that curve, not by its AQL alone.
Probability of acceptance
Pa = sum from k=0 to c of e^-(np) x (np)^k / k! where np = sample size x defect rate
Zero-acceptance plans have a steep OC curve near zero defects but often use smaller samples, so they can accept moderately bad lots with surprising frequency. Compare full OC curves, not acceptance numbers.
Producer risk is rejecting a lot at AQL quality, conventionally about 5%. Consumer risk is accepting a lot at the rejectable quality level, conventionally about 10%.