Reference · Due diligence
Supplier Vetting Checklist
A written checklist you can send to three shortlisted factories and compare side by side — including the evasive answers that signal a problem.
What evidence should a supplier scorecard require before approval?
Score facts, not adjectives. A usable scorecard records technical fit, quality-system evidence, realistic capacity, documented delivery performance, communication speed, entity risk and total landed cost, with a file reference beside every rating and a "not yet observed" option for anything a new supplier has not demonstrated. Weighted scoring should change with the decision: a custom or regulated programme weights change control above a small price gap. The identity checks behind the entity column are in the factory audit checklist.
Supplier selection fails in a predictable way: the buyer asks questions that are easy to answer well, everyone answers them well, and nothing is learned. The checklist below is built the other way round — each question has a strong answer and a weak answer, and the point is to hear which one you get. Send it in writing. According to [Fisher, Ury & Patton, 2011], negotiants reach better outcomes when they insist on objective criteria rather than trading assertions, and a written record of answers is exactly that.
The path before the first message
Is it a factory, or a trading company?
Both can quote, sample and ship, so the useful question is not the label but where the material is changed. A trader buys a finished unit and resells it; a factory owns at least one process that turns material into product. One question settles it and cannot be talked around: which processes happen inside the building, and can you see the one your product depends on — moulding for a silicone body, SMT for a control board? A trader offers a video of a partner's line; a factory walks you to its own. If the honest answer to "manufacture, trade, or both" is "both", that is a real answer and often the better one for a first order — the failure is only when the word "both" arrives after the deposit rather than before it.
Twenty questions, and the answer that should worry you
| Group | Question | Weak answer to watch for |
|---|---|---|
| Identity | What is your registered legal name and business licence number? | A trading name with no licence to check it against |
| Identity | Do you manufacture, trade, or both — and for which components? | "We can do everything" with no in-house detail |
| Capability | Which processes happen on site? | No answer about subcontracted moulding or coating |
| Capability | What is monthly capacity for this product family? | A number with no relation to the line you are standing in |
| Quality | Walk me through your inspection stages | "No problem, our quality is very good" |
| Quality | What is your measured outgoing defect rate? | A figure they cannot produce records for |
| Materials | Who supplies your silicone, and from which grade? | "We use high-quality silicone" |
| Materials | Is the silicone platinum-cured or peroxide-cured? | Not knowing the difference |
| Compliance | Which third-party laboratory issues your material reports? | Internal reports presented as third-party evidence |
| Compliance | Can you name the test method behind each certificate? | Certificates referenced with no method |
| Commercial | What are the separate minimums for product, branding and packaging? | One blended number that hides the real constraint |
| Commercial | Are tooling costs quoted separately from unit price? | Tooling buried in the unit price |
| Tooling | Who owns the mould I commission? | Anything short of full buyer ownership in writing |
| Terms | What supports a rush order, at what cost? | A promise to accelerate without a stated price |
| Terms | How long is your quote valid, and what moves it? | No validity window |
| Logistics | Which Incoterms do you quote, and can you show all three? | Only one term offered |
| Logistics | What documents ship with the goods? | Discovering a missing document at customs |
| Aftercare | What is your written warranty and its start date? | A verbal assurance of support |
| Aftercare | How are disputes resolved, and in writing? | No stated process |
| Channel | Do you sell direct to consumers in my market? | A direct channel that will compete with yours |
Two of these are answered better on a call than in a document, and both have a way to keep them checkable. Ask for a scheduled live walkthrough — telephone the contact at an agreed time and have them walk, without cutting, from the entrance sign past the material store to the line that would run your order. A recorded tour answers a different question: it shows what the factory chose to film. And the sample, once you approve it, should stop being "a sample" and become the golden sample named in writing, with the date, the specification revision and the colour reference recorded against it, because that is the object a pre-shipment inspection compares the production run to.
Turning the answers into a scorecard
The checklist above tells you what to ask. A supplier scorecard — the same idea procurement teams run as a weighted grid — tells you how to compare the answers across three or four candidates without the comparison collapsing into a price column. Each dimension below is scored 1 to 5 against the evidence the checklist produced, then multiplied by a weight that reflects how much that dimension decides whether the relationship survives contact. The grid is the discipline that stops a charming call from beating a merely complete one.
| Dimension | What the score reflects | Weight |
|---|---|---|
| Quality system | ISO 9001 scope, documented defect-rate records, 100% final inspection | 20% |
| Capacity & lead time | Stated monthly capacity vs your volume, a history of hitting dates | 15% |
| Compliance & documents | Named third-party laboratories, CE/RoHS/FDA cited to a method | 15% |
| Commercial clarity | Tooling quoted separately, three minimums stated apart | 12% |
| IP & tooling protection | Buyer-owned tooling in writing, an NDA before any spec | 12% |
| Responsiveness | Time to answer the brief, clarity under follow-up | 10% |
| Logistics & Incoterms | Offers both FOB and DDP, the document set stated | 8% |
| After-sales | A written warranty, a named dispute process | 8% |
Scoring a candidate
References
- Fisher, R., Ury, W. & Patton, B. (2011). Getting to Yes: Negotiating Agreement Without Giving In, 3rd ed. New York: Penguin Books.
- Juran, J. M. & Godfrey, A. B. (1999). Juran's Quality Handbook, 5th ed. New York: McGraw-Hill.
- Christopher, M. (2016). Logistics & Supply Chain Management, 5th ed. Harlow: Pearson Education.
- Monczka, R. M., Handfield, R. B., Giunipero, L. C. & Patterson, J. L. (2015). Purchasing and Supply Chain Management, 6th ed. Boston, MA: Cengage Learning.
Questions on this reference
What should a supplier questionnaire ask that a checklist does not?
A supplier questionnaire should ask for evidence you can verify rather than for assurances. Ask for the issuing body and number on the certificate so you can check it at source, the name of the account manager you will actually deal with, and the last three inspection reports. Factory vetting is the part a questionnaire cannot do: the document set and a walk through the material store rarely agree.
What does supplier due diligence look like for a first order?
Smaller than it sounds. Company registration, one certificate verified at source, a video walkthrough with the line running, and a paid sample order you inspect yourself. Supplier due diligence before the deposit is the whole of it, and each of those four items removes a failure mode that no contract clause recovers from afterwards.
How quickly should a factory answer this?
A factory with its documentation in order answers within a business day. Slowness is not always evasion — it can mean a small team — but it should be explained rather than ignored.
What is the single most useful question to ask?
Who makes the product, and who receives the payment? If those are two different companies, you are buying from the second one and auditing the first. Everything else on the checklist follows from that answer.
Is a business licence enough to verify a factory?
No. It proves a registered entity exists, not that it manufactures anything, and not that the entity is the one you will be paying. Pair it with a live walkthrough and a report number you can check with the issuing laboratory.
Should I visit before or after wiring a deposit?
Before. A visit after the deposit verifies a supplier you have already paid, which is a dispute rather than due diligence. The audit checklist is what to do once you are on the floor.
What is the difference between the checklist and a supplier scorecard?
The checklist is the input — twenty questions you send in writing to every candidate. The scorecard is the comparison: the same answers scored 1 to 5 on a weighted grid so three or four candidates become one ranked shortlist. Run the checklist first; the scorecard is meaningless without the written answers underneath it.
How should I weight a scorecard for this category?
For a body-contact device, weight quality system, compliance documents and IP/tooling protection above price and responsiveness — those three are what end a relationship, not the unit cost. The weights on this page are a starting point; the discipline that matters is scoring every candidate on the same grid, not the exact percentages.
Next: what one day on the floor proves — or who runs the line behind this range.
The list is only worth the answers it produces. How to choose a manufacturer puts these questions in the order that ends a shortlist fastest, the red flags are the answers that should, and where to send the brief is where you ask us the same twenty questions rather than reading our version of them.
Putting this reference to work
This page is the data. The four sections below are where it changes a decision: the terms it is quoted alongside, the guide that explains the reasoning, and the models the figures apply to.