AQL Sample Size for Lot 2,400 — GI Inspection at AQL 1.5

ISO 2859-1:1999 Table II-A · Cross-verified against QIMA reference
Lot size 2,400 units
Inspection level GI
AQL level 1.5
Code letter G
Sample size 32 garments
Accept if defects ≤ 3
Reject if defects ≥ 4

What this means

For a production lot of 2,400 garments at GI inspection level with an AQL of 1.5 (major (strict) defects), ISO 2859-1 requires the buyer's QC inspector to pull 32 garments at random from across the lot. If they find 3 or fewer defects, the entire lot is accepted. 4 or more defects means the lot is rejected — the factory must then sort 100% of the lot, repair defective pieces, and re-present for inspection.

Inspection level note: Reduced inspection — used for low-risk products or trusted suppliers.

AQL tier: Stricter than industry standard major — used by premium brands.

Accept / reject decision table

Defects found in sampleDecision
0 defectsACCEPT
1 defectACCEPT
2 defectsACCEPT
3 defectsACCEPT
4 defectsREJECT
5 defectsREJECT

Worked example — your shipment

Suppose your factory has produced 2,400 garments for a buyer who specified GI / AQL 1.5. The buyer's inspector arrives, opens 5-8 cartons at random, and pulls 32 garments across them.

If the inspector finds 3 defects in those 32 garments → lot ACCEPTED, container ships.

If the inspector finds 4 defects → lot REJECTED. You sort 100% of 2,400 pieces, repair, and re-present in 2-3 days.

How this combination compares

This is the GI / AQL 1.5 combination — the major (strict) sampling plan for GI inspection. If your buyer's PO sheet specified different parameters, here are the adjacent plans:

FAQ for Lot 2,400 · GI · AQL 1.5

What if I find exactly 3 defects?

3 defects = ACCEPT. The accept number is the maximum number of defects you can have in the sample without rejecting. Exactly at the limit is still acceptable.

What if I find 4 defects?

4 defects = REJECT. The reject number is the lowest defect count that fails the lot. There is no "borderline" — anything ≥ 4 triggers a reject.

Can I argue an inspection where I found 4 defects?

You cannot argue the math — the accept/reject thresholds come from the ISO 2859 statistical tables. What you can argue is the classification of each defect. If the inspector marked something as a Major defect that your buyer's spec sheet calls Minor, push back with the spec sheet in writing.

What's the underlying acceptance probability at AQL 1.5?

ISO 2859-1 plans are calibrated so that lots actually at the AQL value get accepted ~95% of the time. So a lot truly at 1.5% defect rate has a 95% chance of being accepted by this plan. Lots at 2× the AQL get rejected most of the time.

Use this in your own QC software

The same logic is published as a free MIT-licensed package:

$ npm install garment-aql-calculator
$ pip install garment-aql-calculator

// Node.js
const { calculateAQL } = require('garment-aql-calculator');
calculateAQL({ lotSize: 2400, inspectionLevel: 'GI', aql: 1.5 });
// → { codeLetter: 'G', sampleSize: 32, acceptNumber: 3, rejectNumber: 4 }