An electronics manufacturer buys memory devices in lots of 30,000 from a supplier. The supplier has a long record of good quality performance, with an average fraction defective of approximately 0.10%. The quality engineering department has suggested using a conventional acceptance-sampling plan with n = 32, c = 0.
N = 30,000; average process fallout = 0.10% = 0.001, n = 32, c = 0
(a) Draw the OC curve of this sampling plan.
(b) If lots are of a quality that is near the supplier’s long-term process average, what is the average total inspection at that level of quality?
(c) Consider a chain-sampling plan with n = 32, c = 0, and i = 3. Contrast the performance of this plan with the conventional sampling plan with n = 32, c = 0.
(d) How would the performance of this chain-sampling plan change if we substituted i = 4 in part (c)?