HomeInsights › Supplier quality

Packaging Defect Classification and AQL Inspection Guide

Define the consequence first, then select a documented sampling plan and decision rule for the actual lot.

Updated 13 September 2026 · Scope: quality-plan framework; buyer QA/statistics owners must approve severity and sampling for each SKU

Three separate decisions

DecisionQuestionOutput
SpecificationWhat must the packaging do and how is each requirement measured?Approved drawing, material/performance specification and test method.
ClassificationWhat is the consequence when a requirement is not met?SKU-specific critical, major and minor defect catalogue with examples.
Sampling/dispositionHow will a lot be sampled and what happens at each result?Current plan with sample size, Ac/Re, authority, segregation and reinspection rules.

Combining them into “inspect to AQL” leaves the most important information missing. Download the blank defect classification template (CSV) and link every defect code to the governing specification.

Define severity from consequence, not appearance

A defect is not critical merely because it looks severe, and a small visual issue can be critical if it creates a safety, legal or traceability failure. Define the consequence for the intended food, load, equipment, route and market. If classification differs by SKU, keep separate rows or a clear applicability field.

SeverityDecision principleIllustrative questions—not universal classifications
CriticalCould create an unacceptable safety, regulatory, contamination, traceability or use hazard.Wrong regulated text or product identity? Foreign sharp object? Material not approved for intended contact? Missing traceability where required? Closure failure that creates an unsafe use?
MajorCould cause package failure, product loss, line stoppage, serious customer rejection or inability to perform the intended function.Open seal? Missing perforation zone? Box joint/lock not engaged? Dimensions prevent packing? Barcode required for the workflow cannot be verified? Print obscures mandatory data?
MinorDeparts from the approved standard without materially affecting safety or primary use under defined conditions.Limited cosmetic variation within an agreed boundary? Noncritical print blemish? Small alignment shift outside visual target but away from required fields?

Product-family prompts

FamilyFunctional areas to classifyEvidence
Produce bagsFilm identity/gauge, dimensions, seal/zipper, perforation, leakage, print, barcode, odor/contamination, roll/wicket functionMaterial/lot record, measurement method, seal/perforation data, line trial, approved artwork.
Corrugated cartonsBoard/combination, dimensions, score/slot, joint, print, vent/drain, warp, compression, moisture condition, glue/stapleBoard and finished-box tests, drawing, conditioning, pack/pallet trial.
PP corrugated boxesSheet thickness/gsm/flute, dimensions, cut/score, weld/rivet/lock, handle, base/lid, vent/drain, print, assemblySheet record, finished construction, load and route validation.
Reusable totesCrack, edge, handle, drain, surface/cleanability, label/traceability, dimensional distortion, prior repairInspection after wash/dry, reject limit, loop identity and repair authorization.

Write a defect row that two inspectors can use

Each row should include a stable defect code, product/SKU applicability, feature, severity, plain definition, measurement or visual method, sample preparation, numeric/visual limit, reference drawing/spec clause, boundary examples, count rule, disposition and escalation owner. State whether several occurrences on one unit count once by unit or separately by defect; ambiguity changes the result.

What AQL means—and does not mean

ISO 28590 introduces the ISO 2859 family and selection of attribute sampling systems. The ISO catalogue lists ISO 2859-1:2026 for lot-by-lot inspection schemes indexed by acceptance quality limit. Use the current purchased standard and qualified statistical review.

AQL is an index used with a specific scheme; it is not a contractual shortcut meaning “this percentage of defects is allowed in every lot.” A sampling plan accepts some lots that contain nonconforming units and rejects some lots that may be relatively good. Producer and consumer risks, lot formation and the full rules matter. Do not copy a sample-size table from an undated web image.

Fields required before drawing a sample

FieldWhat to record
LotSKU/revision, supplier/plant, line/shift, production period, material lots and quantity; rules for mixed or interrupted production.
Inspection unitOne bag, roll, carton, box, bundle or other unit; how multiple cavities/panels are treated.
Standard and editionExact procedure, revision and contract hierarchy.
Inspection statusNormal, tightened, reduced or other applicable state and who determines transitions.
Level/planGeneral or special level; single/double/multiple plan as approved.
IndexAQL, LQ or another basis matched to the contract and lot context.
Sample and Ac/ReSample size and acceptance/rejection numbers for each defect class.
RandomizationHow units are selected across pallets, rolls, cartons, time and positions.
Destructive testsSeparate sample needs and whether tested units return to the lot.
DispositionAccept, reject/hold, screen, rework, concession or other options and authority.

Inspection workflow

  1. Verify identity: PO, SKU, drawing/artwork revision, supplier, plant, lot and quantity.
  2. Confirm plan: current standard, status, level, sample, Ac/Re and classes before seeing results.
  3. Randomize: select across the lot; do not take only the easiest top cases or the supplier’s prepared samples.
  4. Condition and test: follow the referenced preparation, environment, instrument and method.
  5. Record raw observations: unit IDs, defect codes, measurements, photos and retests; do not store only pass/fail.
  6. Apply count rules: classify consistently and escalate ambiguous or potentially critical findings.
  7. Make the lot decision: use the predefined decision rule; record authorized exceptions separately.
  8. Control material: identify, segregate and protect rejected/held stock from accidental use.
  9. Close evidence: retain report, sample/photographs, deviation, corrective action and release authority.

Reinspection is not repeated sampling until a lot passes

If a lot is rejected, define whether it may be screened, reworked or resubmitted; how its identity changes; what evidence is required; and which plan applies. Preserve the original result. Repeatedly drawing new samples from unchanged material changes the decision risk and creates a biased history.

Corrective action should connect defect to process

A response should contain containment scope, affected lots/shipments, verified disposition, defect reproduction, root-cause evidence, corrective action, owner and effectiveness check. Examples of useful process evidence include seal-temperature/pressure/time records, perforation-tool checks, plate/cylinder and artwork revision, board/tension/moisture data, die/score measurements, weld/rivet settings and training/change records.

Acceptance sampling does not replace prevention

Incoming inspection provides a lot decision at stated risk. It cannot guarantee every item, and a passing sample does not demonstrate stable capability. Combine it with approved-supplier controls, first-article review, material and process traceability, in-process data, maintenance, retained samples, complaint/route feedback and formal change control. Tighten source controls when a defect is difficult to detect or its consequence is high.

Common mistakes

Frequently asked questions

Is AQL an allowed defect percentage?

No. It indexes a sampling scheme. The plan and risks depend on the current procedure, lot, inspection level/status, sample size and Ac/Re rules.

Who sets severity?

The buyer’s applicable product, quality, safety, regulatory and operations owners should approve it from consequence. The supplier may propose examples but should not define the buyer’s risk alone.

Can sampling replace process control?

No. It supports a lot decision. Prevention, traceability, process data, corrective action and change control remain necessary.

Build the quality plan around the approved SKU

Send the drawing, material and performance specification, artwork, route, lot structure and customer requirements. Fuxing can map manufacturing controls and sample evidence for review.

Request a pre-production quality plan →