Factory visits are naturally biased toward normal conditions. The line is prepared, the best samples are available, and the people who present the company know the preferred story. None of this makes the visit useless. It means the buyer must deliberately introduce questions about variation, failure, and responsibility.
The strongest answers are rarely perfect. They are specific. A mature supplier can describe what happened, how the problem was contained, why the existing control failed, what changed, and how that change was verified. A supplier with weak control usually returns to slogans: strict quality, advanced equipment, experienced workers, no major problems.
1. Show us a recent nonconformance from this process
Do not ask whether the factory has quality problems. Every factory does. Ask for a recent internal rejection connected to the process you are evaluating. Trace the part, defect, inspection point, disposition, and corrective action.
What this tests: whether problems are recorded; whether the factory distinguishes containment from root cause; whether records connect to the physical process.
2. What can pass inspection and still fail for the customer?
This question tests the supplier’s understanding of specification gaps and functional risk. Experienced teams know that drawings and checklists do not capture every interaction. They should be able to identify characteristics that need functional testing, process control, or clarified acceptance criteria.
Listen for: product-specific failure mechanisms, not generic statements about workmanship.
3. Which part of this order will leave this site?
Subcontracting is normal. Hidden subcontracting is the risk. Ask which components and processes go outside, which provider is currently approved, how changes are controlled, and what incoming evidence returns with the work.
Follow-up: “If that provider cannot meet schedule, who can authorize a replacement, and does the customer get notified?”
4. Who can stop production?
A poster may say that every worker can stop the line. Ask for a recent example. What condition triggered the stop? Who decided? How were affected units isolated? Who authorized restart?
What this tests: whether quality authority exists in practice, especially when schedule pressure and shipment commitments are involved.
5. What changed after your last customer complaint?
The important answer is not the complaint itself. It is the path from field symptom to containment, returned evidence, root cause, changed control, and effectiveness check. If the final answer is “we trained the operator,” ask what in the process now prevents recurrence.
Training can be necessary. When it is the only corrective action, the process often still depends on the same human memory that failed the first time.
6. Who owns our project after sample approval?
The people supporting an RFQ are not always the people supporting production. Meet the engineer, project manager, planner, quality owner, or merchandiser who will handle changes and daily exceptions. Ask what other projects compete for their attention and how unresolved issues are escalated.
What this tests: continuity between sales promises, NPI decisions, and production execution.
7. Which requirement in our package is least clear?
A supplier that says everything is clear may be trying to appear confident or may not have reviewed the package deeply. Strong suppliers usually have questions: ambiguous finishes, missing tolerance logic, uncertain test limits, forecast assumptions, software ownership, packaging criteria, or unclear change authority.
Good signal: the supplier can distinguish a missing input from a proposal it is qualified to make.
8. What does the quoted price assume will go right?
This question opens discussion around yield, sample rounds, buyer response time, material availability, tooling corrections, line utilization, order cadence, and accepted variation. It is often more productive than asking only what is excluded.
Follow-up: “If that assumption is wrong, what changes—price, lead time, specification, or all three?”
9. If the product fails after delivery, what happens in the first 24 hours?
Warranty language is not a recovery process. Ask who receives the report, what information is needed, who can provide remote triage, how stock is contained, whether replacement parts are local, when an engineer can travel, and how temporary action becomes permanent correction.
For machinery and automation, include software backups, remote access, site safety, spare parts, time zones, and authority to modify the system. For products, include traceability, batch containment, replacement logistics, customer communication, and returned-sample analysis.
Do not turn the visit into an interrogation
These questions work best when connected to the buyer’s actual risks and asked with context. Explain that the objective is to reduce ambiguity before both parties invest. Give the supplier time to bring the right people and records into the discussion.
Also allow the supplier to question the buyer. A serious factory should challenge unrealistic tolerances, incomplete forecasts, rushed timelines, undefined acceptance criteria, and late design changes. Diligence runs in both directions.
A visit becomes decision-grade when the buyer can explain not only how normal production runs, but how the organization detects, contains, decides, recovers, and learns when it does not.