Last updated: 16 September 2026
Quick answer. A factory audit compares what a site actually does against criteria you set in advance; it produces evidence and findings, not a pass mark. Agree the scope and criteria, request the records, watch live production instead of staged areas, trace a finished part back to its material lot, and classify every finding as major, minor or observation.
Editorial position: China Custom Parts is an independent sourcing knowledge site — not a factory, not a marketplace, not a directory. This page publishes no factory list, no company name and no supplier ranking. It teaches you how to audit any site yourself, and every factual claim is traced to an official source in the source table at the end.
An audit is a structured comparison. You define the subject, the criteria — your drawing, your tolerances, your market's requirements, the supplier's own procedures — and the evidence rule: a finding needs objective evidence, not an impression. What comes out is a set of findings you can act on. What does not come out is a guarantee about the units that ship next month.
Two standards give you the vocabulary, and they do different jobs. ISO 19011 is guidance on auditing management systems; ISO/IEC 17021-1:2015 sets the requirements for the bodies that audit and certify management systems and describes management system certification as a third-party conformity assessment activity. If you need a certificate that a market or a customer recognises, that third-party route is the relevant one. If you need to know whether a site can make your part, you need your own audit, run against your own specification.
This distinction matters because the two are constantly confused. A management-system certificate tells you that an accredited body audited a system for a named legal entity, at a named site, within a named scope. It does not tell you that your part meets your drawing, and ISO states plainly that it does not perform certification or issue certificates. Check one detail on every certificate you receive: the edition of the quality management standard it names. The 2015 edition of ISO 9001 has been withdrawn and replaced, and ISO advises organisations certified to it to consult their certification body about transition arrangements.
An audit answers what a certificate cannot: which entity makes the part, on which machines, measured with which instruments, traceable to which material lot, and what happens when something goes wrong.
Send the request list before the visit and set a deadline, so that missing records become a finding rather than an excuse. Ask for files, not descriptions, and check the items with a public register against that register.
A workable first request list:
| # | Document or record | What it lets you check |
|---|---|---|
| 1 | Business licence showing the registered name and the unified social credit code | Whether the contracting entity exists and matches the invoice and contract |
| 2 | Registered business scope and public-list standing | Whether production entries appear, and whether the entity sits on an abnormal-operations or serious-illegal-and-dishonest list |
| 3 | Certificates with certificate number, issuing body and scope | Who certified what, for which legal entity and site, and whether the certificate is still valid |
| 4 | Product certifications and listings claimed for your product | Whether the claimed listing or approval names the product you are buying |
| 5 | Organisation chart, quality manual section list and process map | Who owns quality, who can stop a shipment, and how the process flows |
| 6 | Control plan, inspection instruction and sampling method for the operations in your process | Whether acceptance criteria exist in writing, and whether they match yours |
| 7 | Calibration register for gauges used on your features | Whether the instrument that measures your tolerance is itself controlled |
| 8 | Material certificates for the lots actually consumed, not a generic mill certificate | Traceability from your delivered parts back to a heat or lot |
| 9 | Incoming inspection records for the material and the bought-in components | Whether the site checks what it buys, and what it does when a lot fails |
| 10 | Nonconformance, rework, scrap and customer-complaint records for the last periods | Whether the system closes problems or only records them |
| 11 | Subcontracting and outsourcing list, with the operations sent out | Which parts of your process you have not yet seen |
| 12 | Tooling register: who owns each tool, where it is held, and its maintenance status | What happens to your tool if the relationship ends |
Two of these are worth verifying without the supplier's help, because both are public: the national enterprise credit information publicity system, which publishes enterprise credit information with separate registers for the abnormal operations list and the serious illegal and dishonest list, and the national standards full-text system. You need nobody's permission to look at either.
Certificates need the same treatment. The accredited-certificate database cross-checks that the certificate is valid, that the certification body was accredited to issue it, and that the accreditation body is a recognised signatory for that standard; certificates issued inside China can be checked in the national certification and accreditation public service platform, and product listings in the listing body's own verification tool. For the European Union, notified bodies are listed in NANDO, which warns that so-called voluntary certificates are not a recognised means of proving compliance and have no value in checks by market surveillance or customs.
Auditing is sampling. You cannot read every record or measure every unit, so the audit is only as good as the selection rule you state in advance.
Sample the records by tracing, not by browsing. Pick one finished part in the warehouse and walk it backwards: to its packing record, its final inspection record, the in-process inspection at the operation that created the critical feature, the material certificate for the lot consumed, and the incoming inspection of that lot. Then walk one order forwards from the purchase order to the delivered part.
Sample the units by an agreed plan. Where you are judging conformance by attributes — pass or fail against a requirement — the plans that define how many units to inspect and how many failures to allow are published in national and international sampling standards. This page reproduces none of those tables, and a table taken from a website is not evidence: obtain the current edition from the standards body, and confirm the specific sampling plan with your inspection provider before the order runs. Settle in writing the level of inspection, the acceptance and rejection rules, the switching rules if the plan has them, and what happens to a rejected lot.
Size the sample by risk, not by convenience. Decide in advance which features are critical, major and minor, and let that classification drive both the sample and the disposition. Then randomise: a sample the factory selects itself is not a sample.
Treat measurement as part of the sample. A measurement is only evidence if the instrument is in calibration and the method is stated. ISO/IEC 17025 sets the competence, impartiality and consistent-operation requirements for testing and calibration laboratories, and accreditation bodies use it as the criterion for accrediting them; when you outsource testing, ask for a report from a laboratory that meets it, and ask which method was used.
Plan the walk so that the factory cannot prepare the whole site for you: arrive unannounced if the contract allows, or vary the announced time, and ask to see the operation running rather than the showroom.
A trading company is not automatically the wrong partner. What is unacceptable is not knowing which model you are dealing with, because it changes who you can escalate to, who holds your tooling, and how quickly a quality problem can be corrected. No single test is conclusive; use them together and treat the combination as the answer.
| Test | Points to a factory | Points to a reseller |
|---|---|---|
| Registered scope | Production entries in the business scope | Wholesale, retail and import-export entries only |
| Certificate holder and site | Certificate names the entity and the site you visited | Certificate names a different company, or an address that is not the production site |
| Production knowledge | Staff can describe routing, setups, fixtures, gauges and typical failure modes without notes | Answers stay at commercial level and are routed back to "the factory" |
| Tooling and equipment | Site holds tooling, maintenance records and gauge control for your operations | Site has no tooling or measurement capability for the claimed operations |
| Contracting chain | The entity that manufactures, quotes and invoices is the same, or the difference is disclosed in writing | You are told a different entity manufactures only after you ask twice |
| Live access | Unrestricted walk-through, and agreement to a scheduled video call showing production at a time you choose | Access is limited to a showroom, or video material is pre-recorded |
Two habits protect you in either case: ask which legal entity manufactures, which quotes and which invoices — in writing, and early; and write the escalation route and audit rights into the contract. If you are still choosing between candidates, our guide to finding a manufacturer in China covers the public records you can query before you visit.
An audit report is a management document, not a travel diary: it must be reproducible by someone who was not there, and it must be possible to close. A workable structure:
| Report section | What belongs in it |
|---|---|
| Identification | Report number and revision, audit dates, sites and areas visited, and the entities audited |
| Scope and criteria | The product, process or system covered, and the documents the findings were measured against, with revisions |
| Method and limits | Who took part, what was inspected and how the sample was selected, and what the audit did not cover |
| Findings | Each finding as a numbered statement of fact, with objective evidence (record reference, measurement, photograph, interview role) and the criterion it breaches or satisfies |
| Classification | Major, minor or observation, with your definition of each stated in the report so the classification is not arbitrary |
| Corrective action request | What must be done, by when, and what evidence of closure you will accept |
| Positive findings and capability notes | What the site demonstrably does well, including equipment and skills relevant to your part |
| Conclusion | Whether the site is suitable for the intended scope, and on what conditions |
| Distribution and confidentiality | Who receives it, and how long it is retained |
Three rules make the difference between a report that is argued about and one that is acted on. Findings must state facts, not judgements: "the calibration label on the gauge used for this feature was expired at the time of audit" rather than "calibration is poor". Every finding must cite the criterion. Every major finding must require a root-cause analysis, not just a fix, with a follow-up that verifies the action worked. Close the loop in writing: agree the plan and the dates, ask for evidence, then verify — a returned corrective-action form is a statement of intent, and only re-inspection or a documented review of records turns it into evidence.
The audit tells you whether the system can produce your part; inspection tells you whether the units you bought conform. They are separate activities with separate records, and the second needs its own acceptance criteria agreed before production. Our guide to incoming and outgoing quality control covers the inspection side — sampling boundaries, first-article approval, inspection reports and material certificates, and nonconforming product.
Send us the requirement rather than a finished specification, and we will tell you what is missing — what a drawing still needs to specify, which records to request first, and which verification steps to complete before a supplier starts quoting.
Request a quote → Attach the drawing, state material and finishing requirements, and describe how the part is used and where it will be sold.
Last updated: 16 September 2026.
Define scope and criteria first, then cover the entity and its registration, certificates and claimed listings, the documents behind each operation in your routing, calibration and measurement, material traceability, nonconformance handling, tooling ownership and subcontracting. On site, cover live production, in-process inspection, quarantine and dispatch. The audit should end with findings classified against your own definition, plus corrective-action requests.
Sample records by tracing — one delivered part backwards to its material lot, one order forwards to the dock — and sample units against an acceptance plan you have agreed in writing, with the level of inspection and the acceptance and rejection rules stated. This site publishes no sampling table. Obtain the current edition from the standards body or have your inspection provider state the plan it will use, and confirm the specific plan with that provider.
Use several tests together: whether the registered business scope contains production entries, whether the certificate names the entity and the site you are standing in, whether the site holds tooling, gauges and maintenance records for your operations, whether staff can describe routing and failure modes without notes, and whether the manufacturing, quoting and invoicing entities are disclosed. No single test is conclusive, and a disclosed intermediary is preferable to an undisclosed one.
Identification, scope, criteria with revisions, method and sampling, findings stated as facts with objective evidence and the criterion each one cites, a stated classification of major, minor and observation, a corrective-action request with a deadline and closure evidence, positive findings, a conclusion on suitability, and distribution terms. Every major finding should require root-cause analysis, and closure should be verified rather than accepted on a returned form.
All sources retrieved 16 September 2026. This page is an independent reading of the sources listed; the standards and official pages themselves are the specification.
| Fact used on this page | Source |
|---|---|
| S2 | SAMR / openstd https://openstd.samr.gov.cn/bzgk/std/ |
| S3 | IAF CertSearch（International Accreditation Forum） https://www.iafcertsearch.org/ |
| S4 | ISO/IEC https://www.iso.org/standard/61651.html |
| S5 | ISO https://www.iso.org/standard/62085.html |
| S6 | ISO https://www.iso.org/certification.html |
| S7 | ISO/IEC https://www.iso.org/standard/66912.html |
| S8 | European Commission（Single Market Compliance Space） https://webgate.ec.europa.eu/single-market-compliance-space/notified-bodies |
| S9 | ISO https://www.iso.org/standard/70017.html |
| S10 | ASTM International https://www.astm.org/membership-participation/technical-committees/committee-f16 |
| S11 | UL Solutions https://productiq.ulprospector.com/en |
| S12 | ISO ｜ ANSI / ASQ https://www.iso.org/standards.html ｜ https://webstore.ansi.org/ |
| S14 | SAMR / openstd — GB 32100-2015 standard record https://openstd.samr.gov.cn/bzgk/std/newGbInfo?hcno=24691C25985C1073D3A7C85629378AC0 |
Independent resource. This page is published by an independent information resource. It is not a factory, broker or marketplace, and no prices, minimum order quantities, lead times or supplier lists are published. Where a figure or a requirement depends on a standard or an official rule, the standard or the official page is the specification — verify the current edition before you commit to a purchase decision. Sources used for this page are listed below and were retrieved on 16 September 2026.