Quality Control for Thai Manufacturing: AQL & Inspections
Quality is not an inspection at the end. It is a set of agreed limits written before production, checked while the line runs, and verified before the container is sealed. Buyers who only book a final inspection are paying to discover problems too late to fix them cheaply.
The four control points
- First article / pre-production sample. One unit made with production tooling, production material and production process — approved in writing and kept as the golden sample by both parties.
- Incoming material inspection. The factory checks resin, steel, fabric or components against spec on arrival. Ask to see the records, not the policy.
- During production inspection (DUPRO). Booked at 20–30% output. This is the only inspection that can still change the outcome of the lot.
- Final random inspection (FRI). Booked at 100% produced and at least 80% packed, using AQL sampling.
AQL in plain terms
AQL (Acceptance Quality Limit, ISO 2859-1) sets how many samples to pull and how many defects allow the lot to pass. The common consumer-goods standard is General Inspection Level II with:
| Defect class | Typical AQL | Meaning |
|---|---|---|
| Critical | 0 | Safety or legal — never acceptable |
| Major | 2.5 | Would cause a return or complaint |
| Minor | 4.0 | Cosmetic, unlikely to be noticed |
Tighten to 1.0/2.5 for regulated, medical or premium goods. State your AQL in the purchase order — not in an email — so a failed lot has a contractual consequence.
Writing a defect classification list
Generic AQL means nothing without a defect list specific to your product. For each likely defect, state the class and the limit: scratch length in millimetres, permitted colour deviation as a Delta-E against the master, torque range, weld penetration, stitch density. Photograph accepted and rejected examples and attach them to the PO.
Functional and safety testing
Sampling checks appearance and dimensions. It does not check that a product survives its life. Add drop testing, carton compression, cycle testing on moving parts, electrical safety, and material declarations for your destination market. For US-bound goods, align with your CPSC or FDA obligations before the first run.
When a lot fails
Agree the remedy in advance: 100% sorting at the factory's cost, rework with a re-inspection, discount with written acceptance, or rejection. Never accept "we will do better next time" as closure. Require an 8D or equivalent corrective action report naming the root cause and the process change.
Import vs manufacture
Buying finished stock shifts most process control onto the seller — you inspect what exists. Manufacturing means you own the specification and therefore the defect list. That is more work, and it is also the only route to consistent, defensible quality. See the decision guide and the factory audit checklist.
FAQ
What AQL level should I use for a first order?
Use General Inspection Level II at 2.5 major / 4.0 minor for most consumer goods, and tighten to 1.5 or 1.0 major for regulated, electrical or premium items.
How much does a third-party inspection cost in Thailand?
A standard man-day inspection typically runs USD 250–400 in 2026, plus travel for plants outside Bangkok and the Eastern Seaboard.
Is a during-production inspection worth it?
For a first order, yes. It is the only check that can still change the lot, and it usually costs less than sorting or reworking a finished container.
Who keeps the golden sample?
Both sides. One sealed and signed unit stays at the factory on the line and one with the buyer, with photographs attached to the purchase order so the reference cannot drift.