Which statement best describes the difference between 100% inspection and acceptance sampling?

Which statement best describes the difference between 100% inspection and acceptance sampling?

• A. 100% inspection tests a subset of items; acceptance sampling tests every item.
• B. 100% inspection is faster than acceptance sampling.
• C. Acceptance sampling tests a subset and uses no decision rule.
• D. 100% inspection tests every item; acceptance sampling tests a subset and uses a decision rule to accept or reject the lot.

Answer: (D)

Testing every item versus testing a subset reflects how quality is verified and the trade-offs involved. In 100% inspection, every unit is examined, so defects are very unlikely to slip through and the lot that’s released should be defect-free item by item. But this approach is slow and costly, especially for high-volume production, and may not be practical in many settings. Acceptance sampling takes a different path: only a representative subset of items from a lot is inspected. The decision on whether to accept or reject the entire lot is then based on a predefined plan that specifies how many items to test and how many defects are allowed before the lot is rejected or accepted. This introduces a formal decision rule, balancing the risk of accepting a defective lot against the savings in inspection effort. That combination—sampling a subset and applying a decision rule to release or not release the lot—is why the statement describing this difference is the best description.

Testing every item versus testing a subset reflects how quality is verified and the trade-offs involved. In 100% inspection, every unit is examined, so defects are very unlikely to slip through and the lot that’s released should be defect-free item by item. But this approach is slow and costly, especially for high-volume production, and may not be practical in many settings.

Acceptance sampling takes a different path: only a representative subset of items from a lot is inspected. The decision on whether to accept or reject the entire lot is then based on a predefined plan that specifies how many items to test and how many defects are allowed before the lot is rejected or accepted. This introduces a formal decision rule, balancing the risk of accepting a defective lot against the savings in inspection effort.

That combination—sampling a subset and applying a decision rule to release or not release the lot—is why the statement describing this difference is the best description.