# Question: A supplier ships a product in lots of size N

A supplier ships a product in lots of size N = 8,000. We wish to have an AOQL of 3%, and we are going to use single sampling. We do not know the supplier’s process fallout but suspect that it is at most 1% defective.

(a) Find the appropriate Dodge–Romig plan.

(b) Find the ATI for this plan, assuming that incoming lots are 1% defective.

(c) Suppose that our estimate of the supplier’s process average is incorrect and that it is really 0.25% defective. What sampling plan should we have used? What reduction in ATI would have been realized if we had used the correct plan?

(a) Find the appropriate Dodge–Romig plan.

(b) Find the ATI for this plan, assuming that incoming lots are 1% defective.

(c) Suppose that our estimate of the supplier’s process average is incorrect and that it is really 0.25% defective. What sampling plan should we have used? What reduction in ATI would have been realized if we had used the correct plan?

## Answer to relevant Questions

Construct a normal probability plot of the chemical process yield data in Exercise 3.9. Does the assumption that process yield is well modeled by a normal distribution seem reasonable? Find the mean and variance of the random variable in Exercise 3.27. Reconsider the situation described in Exercise 15.1. How many erroneous accounts must be in the batch of accounts for a random sample of size n = 5 to have a probability of at least 0.50 containing the erroneous account? Find a single-sampling plan for which p1 = 0.01, = 0.05, p2 = 0.10, and = 0.10. Compare the plans developed in Exercise 16.16 in terms of average fraction inspected and their operating-characteristic curves. Which plan would you prefer if p = 0.0375?Post your question