Finding a supplier is easy. Qualifying one is not. A quotation tells you what a company is willing to promise; it tells you nothing about whether they can deliver it repeatedly. This is the sequence we work through, and roughly what it costs in time.
Stage one — desk review
Company registration and how long the entity has actually traded under its current name. Shareholding and whether the operating company is the one you would contract with. Certifications, with expiry dates and the scope statement, which is frequently narrower than the certificate implies.
Financial standing to whatever extent the jurisdiction discloses it. A supplier that cannot fund raw material for your order is a schedule risk regardless of technical competence.
This stage removes a surprising proportion of candidates and costs almost nothing.
Stage two — technical questionnaire
Installed equipment with capacity and age. Which processes are performed in-house and which are subcontracted, because subcontracted steps are where traceability usually breaks. Analytical capability on site versus sent out.
Ask for a process flow for a product similar to yours. A supplier who cannot produce one quickly is telling you something about how the plant is actually run.
Stage three — the site visit
This is not optional, and it is not a tour. Look at the housekeeping in areas nobody prepared for you. Look at whether calibration labels are current. Look at whether the batch records being written now match the format you were shown.
Talk to a line supervisor rather than only the sales manager. Ask what went wrong most recently and what they changed. A plant that can answer that specifically is a plant with a functioning quality culture; one that claims nothing goes wrong is either not measuring or not telling you.
Check storage of incoming materials and finished goods. It is one of the fastest reads on whether a quality system is lived or laminated.
Stage four — samples, then a trial order
Sample material is made under supervision by the best operator on the best day. It establishes capability, not consistency. A paid trial order at meaningful volume, run through normal scheduling, establishes consistency.
Specify how the trial will be judged before it runs, and inspect against your specification rather than theirs.
Stage five — commercial and continuity
Payment terms, incoterms, lead time and what happens when they slip. Capacity headroom, because a supplier running at full capacity has no room for your growth or their own recovery from a problem.
Single points of failure: one qualified operator, one piece of equipment with no backup, one upstream supplier for a critical input. Ask what their plan is when that fails, because eventually it does.
Red flags worth stopping for
Reluctance to permit an unannounced or minimally announced visit. Certificates that cannot be verified with the issuing body. A quotation materially below the market with no explainable structural reason. Unwillingness to name any existing customer, even without disclosing volumes.
None of these is proof of a problem. All of them justify slowing down.
The short version
Qualification is a sequence, not a judgement call. Most unsuitable suppliers are removed in the first two stages at almost no cost; the site visit is where the remaining ones are separated.