AQL (Acceptable Quality Level) is a statistical sampling method defined by ISO 2859-1 (ANSI/ASQC Z1.4). Instead of checking every unit, we inspect a random sample whose size is set by your lot quantity and inspection level (usually General Level II). The lot passes only if defects stay within the agreed limits: typically AQL 0 for critical, 1.5 for major, 4.0 for minor.
Step 1 — agree the criteria up front
Before any visit we confirm your inspection level, AQL limits, and any product-specific acceptance criteria, so the report's pass/fail logic matches your risk tolerance and your retailer's requirements. Nothing is decided on the day.
Step 2 — determine sample size
Lot quantity + inspection level give a sample-size code letter, which sets how many units are drawn at random. General Level II is standard; Level I reduces sampling (lower cost, lower confidence) and Level III tightens it.
| Lot size | Code (GII) | Sample |
|---|---|---|
| 151–280 | G | 32 |
| 281–500 | H | 50 |
| 501–1,200 | J | 80 |
| 1,201–3,200 | K | 125 |
Step 3 — apply acceptance numbers
| Defect class | AQL | Logic |
|---|---|---|
| Critical | 0 | Any critical defect fails the lot |
| Major | 1.5 | Accept/reject number from the Z1.4 table |
| Minor | 4.0 | Accept/reject number from the Z1.4 table |
Normal, Tightened & Reduced inspection
For ongoing programs we apply the Z1.4 switching rules: move a struggling supplier to Tightened inspection, and reward a consistently clean one with Reduced inspection — keeping cost proportional to risk.
Beyond sampling: what we actually test
AQL governs how many units we open; our furniture-specialist protocol governs what we check on each one — moisture content, structural and stability tests, dimensions, function, finish, labeling and packaging. See the sample report and defect library.