What does AQL mean in garment inspection?
AQL stands for Acceptable Quality Limit: the maximum percentage of defective garments that is treated as acceptable when a lot is sampled. AQL 2.5 means a lot with up to 2.5 percent major defects passes on average.
AQL does not guarantee a defect rate in the lot. It sets the probability of acceptance: a lot whose true defect rate equals the AQL is accepted about 95 percent of the time, and a lot with a defect rate well above it is rejected in most samples. The sample size scales with lot size, and the accept number scales with both sample size and the AQL value.
Buyers set three AQL values per inspection, one per defect class. The convention in menswear is 0 for critical defects, 2.5 for major defects and 4.0 for minor defects. The values appear in the purchase order, and the factory produces against them.
How does a pre-shipment inspection sample a lot?
An inspector draws a random sample from the finished, packed lot using the ISO 2859-1 table. At General Inspection Level II, a lot of 3,201 to 10,000 pieces gives a sample of 200 garments, and a lot of 10,001 to 35,000 pieces gives 315.
A pre-shipment inspection (PSI) is the final check, performed when production is complete and at least 80 percent of the goods are packed in cartons. The inspector selects cartons at random across the lot, opens them, and draws garments from each, so that every size and colour is represented in proportion.
| Lot size (pieces) | Code letter | Sample size, Level II | Accept / reject, AQL 2.5 | Accept / reject, AQL 4.0 |
|---|---|---|---|---|
| 281 to 500 | H | 50 | 3 / 4 | 5 / 6 |
| 501 to 1,200 | J | 80 | 5 / 6 | 7 / 8 |
| 1,201 to 3,200 | K | 125 | 7 / 8 | 10 / 11 |
| 3,201 to 10,000 | L | 200 | 10 / 11 | 14 / 15 |
| 10,001 to 35,000 | M | 315 | 14 / 15 | 21 / 22 |
General Inspection Level II is the default level. Level III draws larger samples and gives a tighter result at higher inspection cost, and Level I draws smaller samples. Special levels S-1 to S-4 apply to destructive or costly tests. The inspector also checks measurements on a subset of the sample against the tolerances in the tech pack, together with carton weight, packing method and labelling.
The inspection follows sourcing and supplier management controls that run earlier in the order: fabric testing, in-line checks during sewing and an end-line check on every finished garment.
What separates a critical defect from a major or minor one?
A critical defect makes the garment unsafe or illegal to sell, a major defect makes it unsaleable or visibly unacceptable, and a minor defect departs from specification without affecting use or sale. Critical carries zero tolerance in menswear.
| Class | Definition | Menswear examples | Typical AQL |
|---|---|---|---|
| Critical | Unsafe or non-compliant | Broken needle fragment in the garment, sharp hardware edge, missing fibre-content label where law requires one | 0 |
| Major | Unsaleable or visibly unacceptable | Open seam, hole, wrong size label, stain, wrong colour, measurement outside tolerance | 2.5 |
| Minor | Departure without effect on use | Loose thread over 1 cm, slightly uneven stitching, minor pressing mark | 4.0 |
Classification is agreed before production. A defect list attached to the purchase order states which class each defect belongs to, and the inspector follows the list rather than judging case by case. A measurement outside tolerance is classed as major in most menswear specifications.
What does AQL 2.5 permit in practice?
AQL 2.5 permits 10 major defects in a 200-piece sample from a 3,201 to 10,000 piece lot. The eleventh major defect rejects the lot. Critical defects permit none, and minor defects follow the separate AQL 4.0 limit of 14.
The arithmetic scales with the sample. A lot of 1,000 pieces is sampled at 80 garments, with 5 major defects accepted and 6 rejecting. A lot of 20,000 pieces is sampled at 315, with 14 accepted and 15 rejecting. The percentage of permitted defects in the sample falls near 5 percent at small samples and 4.4 percent at 315, because the accept number is a statistical limit and not a proportion of the sample.
Each defect class is counted independently. A lot with 9 major and 13 minor defects in a 200-piece sample passes, since 9 is within 10 and 13 is within 14. A lot with a single critical defect fails regardless of the major and minor counts.
What happens when a lot fails inspection?
A failed lot is held at the factory. The factory sorts the lot 100 percent, repairs or replaces defective pieces, repacks, and the lot is re-inspected at a fresh random sample. Shipment proceeds only after the re-inspection passes.
Re-inspection takes 3 to 7 days, depending on the defect type and lot size. Rework such as re-pressing or thread trimming is quick, while a systemic defect such as a wrong measurement across a size requires recutting and adds weeks. The cost of sorting and rework falls on the factory under standard purchase-order terms, and the buyer's contract states this.
The report from a failed inspection lists defects by class, photographs each one, and records measurement results. Buyers use the report as the reference for any claim, since it fixes the condition of the goods at the date of inspection. Three inspection results exist: pass, fail and pass on concession, where the buyer accepts a lot with a documented deviation at an agreed price reduction.
Where does AQL inspection fit when sourcing from Bangladesh?
Bangladeshi factories run in-line and end-line quality control as standard, and third-party inspection companies operate in Dhaka and Chattogram, so a buyer arranges a pre-shipment inspection by an independent inspector or attends in person. Buyers who plan a visit to Bangladesh inspect a lot against the AQL table above and review the defect list on site.
Inspection terms are agreed in the order: AQL values per class, inspection level, who appoints the inspector, and who pays for re-inspection. Buyers acquiring garment stock lots apply the same tables to a lot already packed, since the inspection is performed on finished goods and requires no production step. Finished goods are inspected the same way; see jackets currently in stock.