AQL, Critical Defect and Care-Label Mismatch on Denim Jackets
An export house is inspecting a completed lot of 1,200 denim jackets before shipment. The buyer's contract specifies general inspection level II, AQL 2.5 for major defects and zero acceptance for critical defects. A random sample of 80 jackets is drawn. Inspectors find three major defects: two jackets with uneven topstitching at the placket and one with a shade variation between the sleeve and body. They also find one jacket with a broken needle fragment inside the left pocket, and the care label on all sampled jackets says 'machine wash 30°C' while the approved specification says 40°C. The production manager wants to pass the lot because the major-defect count is below the acceptance number and only one critical defect was found. The buyer's shipment window is in four days. The factory has a metal detector at the packing line but it was bypassed during the weekend shift.
1. Using the sample result, determine the major-defect decision and explain the reasoning.
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For a lot of 1,200 at general inspection level II, the sample size is 80 and the AQL 2.5 single-sampling acceptance number is 5, with rejection at 6. The inspectors found three major defects, so the major-defect count is within the acceptance number. On majors alone, the lot would be accepted. That conclusion is narrow: it assumes the three defects are correctly classified and that the sample was truly random. Shade variation between sleeve and body could be treated as a major defect or even a critical appearance defect if the buyer's specification says shade must be uniform within a garment. The production manager is therefore right about the arithmetic but wrong to treat the arithmetic as the whole decision, because the critical defect and label error are separate nonconformities.
2. How should the critical defect and the care-label error affect lot disposition? Explain the difference between AQL sampling and zero-critical acceptance.
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The broken needle fragment is a critical safety defect. The contract allows zero critical defects, so the lot cannot be shipped as it stands, even though the major-defect count is acceptable. AQL sampling does not authorize release when a critical defect is found; it triggers containment. The care-label error is also a nonconformity because the label does not match the approved 40°C specification. Depending on the market, a wrong care label can be a legal or customs issue, not merely a minor sewing error. The lot should be placed on hold, the 1,200 jackets should pass through a functioning metal detector or be physically inspected, and every label should be verified and replaced. The correct disposition is not 'accept because only one critical was found'; it is 'reject the lot pending 100% screening and re-inspection'.
3. Propose containment and corrective actions that can be completed before the four-day shipment window.
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Immediate containment: quarantine the lot, stop packing, repair or replace the three major-defect garments, and run every jacket through a calibrated metal detector with a challenge sample at the start and end of each shift. Open and inspect pockets if the detector cannot prove clearance. Replace all incorrect care labels and verify a sample against the approved specification. Re-inspect the cleared lot and record the results. Corrective action: find out why the detector was bypassed on the weekend shift, restore a lockout or sign-off procedure, and train the packing supervisor. Add a needle-control procedure with broken-needle records and a final detector check. If the four-day window cannot accommodate 100% screening, ask the buyer for a short extension rather than shipping an unverified lot. The cost of screening is far lower than the cost of a needle injury or a rejected shipment.