AQL inspection in China: what the sampling plan can—and cannot—tell a small importer.

AQL inspection in China is commonly used to decide how many units to sample from a finished lot and how acceptance or rejection is determined for classified defects. The current ISO 2859-1:2026 defines AQL-indexed sampling schemes for inspection by attributes. Buyers should use the applicable standard or professional guidance rather than copying an old table from an unrelated checklist.

A sampling plan is only one part of quality control. It does not replace a clear product specification, approved sample, compliance testing or process control. If the inspector does not know what to check, a statistically selected sample can still produce an unhelpful report.

Understand the lot, unit and inspection stage

Define the inspection lot: the quantity presented together for the same decision. Confirm whether all units are finished, packed and available for random selection. If production is incomplete or cartons are staged selectively, the sample may not represent the intended shipment.

Define what counts as one unit. A retail set may contain several components, while a master carton contains many saleable units. The checklist should explain whether completeness, packaging and carton-level checks are evaluated per unit, per set or per carton.

Choose a sampling plan deliberately

Sample size is normally determined from lot size, inspection level and the selected plan. General inspection levels are used for many routine characteristics, while special levels may be used for tests that are costly or destructive. The appropriate level depends on risk, history, product and the decision the buyer needs to make.

Do not interpret a smaller sample as “good enough” simply because the order is small. Conversely, 100% inspection is not automatically perfect: fatigue, inaccessible internal features and poorly defined criteria can still produce errors. Document the selected plan and why it fits the project.

Define critical, major and minor defects

Classify defects by consequence, not appearance alone. A critical defect may create an unacceptable safety, legal or essential-use risk. A major defect can cause likely return, failure or significant customer dissatisfaction. A minor defect departs from the specification without materially reducing normal use.

The exact classification must be product-specific. A sharp edge on a children’s product and a small cosmetic mark on a hidden surface should not share the same category. Compliance professionals should define safety-critical criteria where necessary.

Use acceptance numbers correctly

For each defect class, the selected standard and plan provide an acceptance and rejection threshold for the sample. Count defects consistently; do not silently reclassify them after seeing the result. One unit may contain more than one defect, so the reporting convention should be agreed in advance.

Passing the sample means the observed result met the defined acceptance rule. It does not prove zero defects in the lot, future reliability, legal compliance or performance beyond the tests performed. Rejecting the lot triggers a commercial decision: sorting, rework, replacement, additional inspection or another agreed remedy.

Random selection matters

The inspector should select samples across different cartons and positions rather than accept a prepared display. Record the carton-selection method and quantities. If the shipment contains variants, determine whether they are one homogeneous lot or require separate sampling and reporting.

Connect AQL to the approved sample

The inspector needs the purchase order, current specification, approved visual reference, artwork and defect list. Ambiguous criteria create arguments after the inspection. Review the approved configuration through the golden sample process and organize checkpoints before production with MICStore’s quality inspection service.

Plan what happens after failure

Define who reviews the report, how quickly the supplier responds, whether rework evidence is required and when reinspection is needed. A report without a decision path can delay shipping while storage and booking costs continue. Serious or repeated failures should also trigger supplier and process review.

Document measurements and functional checks precisely

For every measured characteristic, identify the instrument, location, unit and tolerance. A result such as “size OK” is weaker than a table of actual measurements compared with the approved limits. When a function is tested, state the setup, sample condition, duration, repetitions and observed result.

Some checks consume or damage the sample. Decide in advance whether destructive tests use the AQL sample, a separate quantity or laboratory specimens. If testing only a few units because it is expensive, do not present that result as if it represented every unit in the lot. The report should distinguish sampled workmanship, measured characteristics and specialized tests.

FAQ

Does AQL mean the buyer accepts that percentage of defects?

No. AQL indexes a sampling scheme and acceptance decision; it is not a contractual promise that a specific percentage of defective goods is acceptable in every shipment.

Can AQL inspection replace product testing?

No. Routine visual and functional sampling cannot replace required laboratory, safety, durability or compliance testing.

Should every SKU use the same defect limits?

Not automatically. Product risk, customer expectations, supplier history and defect consequences should shape the plan and checklist.