In the past, Alpha Corporation has not performed incoming quality control inspec

Question

In the past, Alpha Corporation has not performed incoming quality control inspections but has taken the word of its vendors. However, Alpha has been having some unsatisfactory experience recently with the quality of purchased items and wants to set up sampling plans for the receiving department to use.

        For a particular component, X, Alpha has a lot tolerance percentage defective of 33 percent. Zenon Corporation, from which Alpha purchases this component, has an acceptable quality level in its production facility of 5 percent for component X. Alpha has a consumer's risk of 10 percent and Zenon has a producer's risk of 5 percent. Refer Exhibit 10.16. (picture below)

When a shipment of Product X is received from Zenon Corporation, what sample size should the receiving department test? (Round up your answer to the next whole number.)

In the past, Alpha Corporation has not performed incoming quality control inspections but has taken the word of its vendors. However, Alpha has been having some unsatisfactory experience recently with the quality of purchased items and wants to set up sampling plans for the receiving department to use.

        For a particular component, X, Alpha has a lot tolerance percentage defective of 33 percent. Zenon Corporation, from which Alpha purchases this component, has an acceptable quality level in its production facility of 5 percent for component X. Alpha has a consumer's risk of 10 percent and Zenon has a producer's risk of 5 percent. Refer Exhibit 10.16. (picture below)

Explanation / Answer

Sample size to be tested (n) = (n*AQL) ÷ AQL

Given: Acceptable Quality Level (AQL) = 0.03
Lot Tolerance Percent Defective (LTPD) = 0.10
For finding, n*AQL, we first need to find LTPD / AQL = 0.10 / 0.03 = 3.333
Now using the Sampling Plan Table for Alpha = 0.05 (acceptable quality level in its production facility) and Beta = 0.10 (consumer's risk), the value closest to 3.549.

n * AQL for 3.549 = 2.613

Sample size = 2.613 ÷ 0.03 = 87.1 - rounding off we get 88

Allowable number of defects in order to accept the shipment = Sample Size * LTPD = 88 * 0.1 = 8.8 rounding off to the previous whole number 8

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.