Shower Tray AQL Inspection: Define Critical, Major and Minor Defects Before Shipment
Wakebath · B2B shower tray decision system
Define the defect, method and authority first; then use a current sampling scheme to make the lot decision.
A practical handoff guide for teams that need a defensible decision—not another supplier brochure.
Short answer: An AQL value is not a defect specification and does not mean an accepted lot is defect-free. Before selecting a sampling plan, define the lot, inspection unit, defect catalogue, severity logic, method, lighting or measurement condition, evidence record and release authority. Use the current ISO 2859-1 tables through authorised access or a competent inspection system, rather than copying an online calculator without checking edition and assumptions. Product standards, approved samples and drawings provide acceptance inputs; they do not automatically create the buyer's lot-inspection plan.
AQL Answers Only One Part of the Decision
ISO 2859-1:2026 defines AQL-indexed sampling schemes for lot-by-lot inspection by attributes. It helps determine a sample size and acceptance/rejection decision under the selected scheme. It does not tell a shower tray buyer:
- what counts as a defect;
- whether a defect is critical, major or minor;
- which AQL or inspection level to choose;
- which drawing tolerance applies;
- whether a laboratory test must be repeated on every shipment;
- whether the inspected units represent one coherent lot; or
- who may release a shipment with an open concession.
Those decisions must be defined before the inspector opens cartons.
Start With a Controlled Lot
| Lot field | Required definition | Why it matters |
|---|---|---|
| Purchase order and line | exact commercial scope | prevents mixing unrelated orders |
| Model and revision | product configuration | a changed drain, surface or tool may require separate treatment |
| Size, colour and texture | variant identity | visual and dimensional methods may differ |
| Factory and production line | manufacturing source | supports traceability and change review |
| Production dates / batches | time and material trace | helps isolate process or raw-material events |
| Packaging revision | shipping configuration | damage and completeness depend on the pack |
| Quantity presented | inspection population | must match the sampling input |
| Rework status | original or re-presented lot | affects history and tightened/escalated controls |
Do not combine models or batches merely to produce a convenient lot size unless the approved sampling and risk plan permits it.
Define the Inspection Unit
One “unit” may mean:
- one unpacked tray;
- one retail carton containing tray and accessories;
- one tray/waste kit;
- one pallet; or
- one complete shower solution.
The unit must match the characteristic being inspected. A carton-completeness inspection cannot be performed on a tray alone. A pallet-label check does not establish the surface condition of every tray inside.
Write the Defect Catalogue Before Choosing AQL
The example below illustrates classification logic. It is not a universal Wakebath acceptance standard.
| Observation | Possible severity question | Required method / evidence | Do not decide from |
|---|---|---|---|
| Crack, delamination or movement under defined load | Can it affect safety, structural function or water control? | approved functional method and escalation rule | appearance photo alone |
| Wrong model, size or drain position | Can the product be installed or sold for the ordered use? | label, drawing and dimensional record | carton name only |
| Drain interface outside released drawing | Can the named waste seal and assemble correctly? | datum-based measurement and fit check | “looks centred” |
| Rim or landing-zone problem | Can the intended enclosure seat and seal? | profile/datum method and interface drawing | general whole-tray flatness statement |
| Surface contamination or mark | Is it removable residue, abrasion, coating damage or structural damage? | controlled cleaning/diagnostic sequence | aggressive spot cleaning before documentation |
| Colour, gloss or texture variation | Is it outside the approved window for the agreed viewing method? | controlled master/instrument and lighting condition | phone auto-white-balance image |
| Missing label or document | Does it affect traceability, market access or customer use? | released label/document matrix | assumption that paperwork can follow later |
| Carton or internal-protection damage | Is product protection or saleability compromised? | pack drawing, product inspection and route criteria | carton appearance alone |
Severity must be use-based
- Critical: buyer-defined condition with potential for serious safety, legal or fundamental compliance consequence. Use sparingly and define the escalation route.
- Major: condition likely to prevent intended installation, function, sale or normal service, or create a material customer complaint.
- Minor: condition that departs from the agreed requirement but is unlikely to materially prevent intended use or sale under the buyer's channel rules.
These descriptions are a planning framework, not definitions copied from ISO 2859-1. The buyer should align them with its product, destination market, contract and risk policy.
Separate Four Inspection Lanes
1. Identity and completeness
Model, size, colour, handing where relevant, batch, labels, waste/accessories, instruction and carton contents.
2. Appearance
Surface contamination, chips, scratches, gloss, colour, texture, exposed repair and visible mould/finish conditions under a defined viewing method.
3. Dimensional and interface
External dimensions, drain coordinates, edge/rim profile, enclosure landing, underside support zones and other controlled drawing characteristics. Use the specified datum and capable measurement equipment.
4. Functional or destructive evidence
Water flow, load/deflection, cleanability, durability, packaging performance or other tests. Some may be audit, type, periodic or change-triggered tests rather than checks on every sampled shipment unit. The control plan must say which.
Do not force all four lanes into one AQL number. Different characteristics can need different sampling, frequency, test specimens or release authority.
Select the Sampling Plan With the Current Standard
Record at least:
- standard and edition;
- lot size;
- inspection level or special level, where applicable;
- single, double or multiple sampling route;
- normal, tightened or reduced state and switching basis;
- AQL for each defined defect class;
- sample size code and sample size;
- acceptance and rejection numbers;
- method of random selection; and
- action for rejection, concession, sorting or reinspection.
Do not reproduce an old table from an unverified website. ISO published the third edition of ISO 2859-1 in January 2026, replacing the 1999 edition and its amendments. A buyer using a calculator or third-party inspection form should verify which edition and scheme it implements.
What AQL does not mean
- It is not a promise that the lot contains only that percentage of defects.
- It is not the same as the measured defect rate in the sample.
- It is not a substitute for 100% controls where law, safety, automation or contract requires them.
- It does not make a poorly defined defect objective.
- It does not certify characteristics that were not inspected or tested.
- It does not remove producer's and consumer's sampling risks.
Make Measurement Results Trustworthy
A number is not evidence unless the method is reproducible.
| Measurement input | Record |
|---|---|
| Characteristic | exact drawing callout or agreed field |
| Datum / support | where and how the tray is referenced |
| Equipment | type, range, resolution and identification |
| Equipment status | calibration/verification status appropriate to the method |
| Environment | relevant temperature, conditioning, lighting or wet/dry state |
| Method | point locations, sequence, force and repeats where relevant |
| Result | value, unit, uncertainty/limitations where required, and pass/fail basis |
| Operator / date | traceable record |
ISO 10012:2026 sets requirements for a measurement-management system intended to support confidence in measurement results. It does not provide shower-tray tolerances; the controlled drawing, product standard or buyer/supplier agreement must do that.
Coordinate the Internal Release
| Role | Before inspection | At result review | Handoff record |
|---|---|---|---|
| Procurement | fixes order scope and commercial consequences | confirms supplier disposition and schedule impact | order/claim decision |
| Technical | releases drawing, methods and interface priorities | reviews dimensional or functional deviations | technical concession or hold |
| Quality | owns plan, defect catalogue and sampling record | validates result and escalation | inspection report and CAPA request |
| Compliance | identifies regulatory/marking checks | reviews any scope or document mismatch | compliance hold/release |
| Logistics | defines pack and labelling controls | reviews damage pattern and shipment risk | pack release or containment |
| Product / Sales | defines approved appearance and channel tolerance | reviews saleability within controlled criteria | appearance decision |
| Sponsor | approves residual commercial risk where authorised | decides on conditional release or rejection | signed decision register |
The inspector should not invent a commercial concession at the factory. The report should make the evidence clear enough for the authorised roles to decide quickly.
Reconstructed Case — Not Wakebath Inspection Data
A 600-unit order contains two sizes and three colours. The buyer sends one instruction: “Inspect to AQL 2.5.” The inspection agency combines everything into one lot, classifies all visible marks as major and checks drain position with an undefined edge reference.
The report shows a rejection, but the team cannot tell:
- which model or batch drove the result;
- whether removable transfer marks were treated as surface damage;
- whether the drawing datum matched the measurement;
- whether the same AQL was intended for missing labels and dimensional fit; or
- who may approve rework and reinspection.
A controlled plan would separate or deliberately stratify the variants, define defect examples, identify the datum, state the edition and sampling inputs, and route appearance, technical and compliance findings to the correct approver. The result might still be rejection, but it would be actionable.
Pre-Shipment Inspection Record
| Field | Entry |
|---|---|
| Buyer plan ID / revision | |
| PO / model / batch / quantity | |
| Standard and edition | |
| Sampling scheme and state | |
| Critical / major / minor criteria | |
| Sample and Ac/Re values | |
| Random-selection method | |
| Identity/completeness result | |
| Appearance result | |
| Dimensional/interface result | |
| Functional/audit-test references | |
| Packaging/label result | |
| Nonconformity photos and map | |
| Rework / containment | |
| Release authority and decision |
Request an inspection-plan gap review
Send Wakebath the order quantity, model/colour mix, destination market, drawing revision, current defect catalogue and intended inspection route through the contact page. Wakebath can return a structured list of missing inspection inputs and role approvals. Selection of the sampling scheme and shipment release remain the buyer's responsibility, with competent inspection and legal/compliance support where required.
Send a controlled input packPrimary references and evidence boundary
- ISO — ISO 2859-1:2026, Sampling procedures for inspection by attributes — Part 1 — Current third edition for AQL-indexed lot-by-lot sampling schemes, published January 2026. The complete normative tables and rules require authorised access. Accessed 2026-09-30.
- ISO — ISO 28590:2017, Introduction to the ISO 2859 series — Current confirmed overview of attribute-sampling systems in the ISO 2859 family. It does not define shower-tray defects or the buyer's commercial risk appetite. Accessed 2026-09-30.
- ISO — ISO 10012:2026, Requirements for measurement management systems — Current measurement-management framework supporting confidence in validity and reliability of measurement results. It does not provide shower-tray tolerances. Accessed 2026-09-30.
- ISO — ISO 9001:2026, Quality management systems — Requirements — Current quality-management framework. A supplier's ISO 9001 certificate does not replace product inspection, current evidence or buyer acceptance criteria. Accessed 2026-09-30.
- BSI — BS EN 14527:2016+A1:2018, Shower trays for domestic purposes — Product-standard scope for relevant shower trays. A product standard is an acceptance input, not a complete shipment-sampling plan. Accessed 2026-09-30.
- ASTM International — ASTM D4169-22 and ISTA — official test-procedure overview — Packaging-performance frameworks that may support pack validation. They should not be reduced to visual carton inspection or applied without matching the route and shipping unit. Accessed 2026-09-30.
Evidence boundary: This article does not reproduce ISO 2859-1 tables, select an AQL, inspection level or defect class for a buyer, or promise a defect-free accepted lot. Critical/major/minor examples are editorial planning examples. The final plan must reflect the controlled product specification, legal and safety obligations, buyer channel, contract, supplier history and authorised current standard.
Editorial status: Review draft. Technical framework and source status checked 30 September 2026. Publication requires final URL, cover and internal-link verification.