Sampling plan practice

Module quiz

8 questions on Sampling plan practice. Answer them all, then check your score before moving on. 6 correct or more is a pass. Your best score is saved on this device, and to your account when you are signed in. This is a self-check, not an accredited assessment.

1. 1. Lot 3,200 pieces. The plan gives a sample of 200 with accept 10 and reject 11 for major defects. You find 9 major and 14 minor. What is the decision?

   Reject: 23 defects in total exceeds 11Accept: majors are 9, below the accept number of 10, and minors are counted against their own planReject: any lot with more than 10 findings failsHold: the result is inconclusive

2. 2. Same lot and plan. You find 11 major defects, and two of them are the same fault on the same operation. What is the decision?

   Accept, because two of them share one causeReject: 11 reaches the reject number regardless of whether the causes are relatedCount the two as one defect and acceptRe-inspect a fresh sample of 200

3. 3. Lot 800 pieces, sample 80, accept 5 reject 6 for majors. You find 5 majors and one broken needle fragment inside a garment. What is the decision?

   Accept: majors are within the planStop the lot: the metal fragment is a critical safety finding handled by procedure, outside the majors countReject: the fragment counts as a sixth majorAccept and add a warning to the report

4. 4. Lot 12,000 pieces presented in three colours. The buyer's plan treats the lot as one. Which sampling approach is right?

   Inspect only the largest colourDraw the sample proportionally across all three colours and cartons, so the sample represents the lotInspect each colour as a separate lot regardless of the buyer's planInspect the first cartons packed

5. 5. The factory offers you 200 pieces they have already selected for inspection. What do you do?

   Inspect them, since the count matches the planDraw your own sample at random from the packed lot; a selected sample tells you nothing about the lotInspect 100 of theirs and 100 of yoursAccept the lot on their check

6. 6. Lot 5,000 pieces, sample 200, accept 7 reject 8 for majors. You find 7 majors, and measurements on 6 pieces are outside tolerance. The programme treats measurement failure as major. What is the decision?

   Accept: 7 majors is within the planReject: the 6 measurement failures are majors too, so the count is 13 against a reject number of 8Accept, because measurements are reported separatelyHold for the buyer to decide

7. 7. A lot fails. The factory sorts 100 per cent, removes the defects and presents it again. How should the re-inspection be handled?

   Pass it without inspection, since it was sortedTreat it as a re-presented lot: a fresh random sample, the plan applied again, and the report stating that it is a re-inspection after sortingInspect only the pieces that were reworkedUse half the sample size

8. 8. Your report says 'accepted with comments' for a lot that exceeded the reject number. Why is that phrase dangerous?

   It is too informalIt records a pass for a lot that failed the plan, so the data is wrong and nobody can see the real defect level laterIt requires the buyer's signatureIt slows the shipment