Selecting a manufacturer: running an assessment you can defend later

Define the scope of supply before you ask who can make it

A shop quoting your product needs to know where its responsibility starts and stops, and so do you. Are you buying labour and machine time against your drawings, or a finished, tested, packed unit with component purchasing included? Who buys the long-lead parts and carries them on their balance sheet? Who owns the test equipment, sets the limits, and decides a unit has failed? Who handles units returned by your customers? Two shops can quote the same product and mean entirely different things by it, and that difference never shows up in the price. Write the scope as a list of activities with a named owner beside each, and issue that alongside the drawing pack.

Criteria that predict how the relationship will actually go

Weighted scorecards reward what is easy to score: certificates held, machines listed, headcount, price. The factors that decide whether this works are harder to put a figure against. Has the shop built something carrying the same failure risks as yours, rather than merely the same shape? Does an engineer answer a technical question directly, or does everything route through a salesperson? How did they behave when you asked for something awkward during quotation? Is their customer mix stable, or dominated by one account whose departure would take the plant with it? Weight those deliberately above unit price, because arithmetic left alone will make the choice for you.

Where you sit in their order book decides how you get treated

A modest programme inside a large plant receives whatever capacity remains once the anchor accounts are served, and its engineering queries join a long queue. The same programme at a smaller shop can be the account paying the rent, which buys attention while concentrating risk: their financial trouble becomes yours, and their growth may outrun their systems. Ask plainly what share of output your volume would represent, and what else runs on the equipment you would depend on. Neither answer disqualifies anyone, but they demand different handling. Being honest with yourself about being a small account is worth more than being promised a priority you will not get.

Putting quotations onto a basis where they can be compared

Offers arrive with different assumptions buried inside them: scrap allowance, material grade, packaging, test coverage, inspection level, tooling charged separately or absorbed into the piece price, freight terms, payment terms, and what happens if volume lands below the assumed level. Rebuild each onto a common basis before looking at totals, and put the same written clarifications to every candidate. A shop that quotes low against a thin reading of your specification is not offering value; it is telling you the work has not been understood, and the gap comes back as change requests once tooling is committed and switching has become expensive.

Who signs the decision, and what the file has to hold

Selection normally involves engineering, operations, quality and finance, each of whom will later recall a different reason why the winner won. Name the decision owner at the outset, record what each candidate was assessed against, keep clarifications in writing, and write down the reservations as well as the strengths. When trouble surfaces a year in, that record is what separates an accepted, known risk from a genuine surprise, and it shapes whether the response is a managed fix or a hunt for someone to blame. It also earns its keep if the choice must be revisited, since the runner-up file is the quickest route to an alternative.

Frequently asked questions

How many candidates should go through a full assessment?

Fewer than most companies begin with. Deep assessment consumes engineering time on both sides, and a candidate who senses they are one of many invests less in understanding your product. Screen widely, then take a small number, often two or three, through sample parts, a site visit and a normalised quotation. If none of them convinces you, widen the screen and run the exercise again rather than settling for the least unconvincing of the shops you happen to have found.

Should we tell a candidate who else we are talking to?

Confirm that the work is competitively quoted; name nobody. Identifying the other bidders invites price theatre and tells a shop precisely how hard it needs to try. It also pushes commercially useful detail about your programme into an industry where people move between employers regularly and talk to one another at trade events. Keep the shape of the process visible, meaning the stages, the evidence you want and the timing, while keeping the participants private.

Can we award without visiting the site at all?

Companies do it routinely where the product is simple and the commitment modest. Exposure rises with how much of the business rides on the outcome. Video walkthroughs, sample parts, third-party assessment reports and reference calls narrow the gap, but each shows you what somebody chose to show. Where the product is complex, the tooling spend material, or a failure would take you off the market for a season, somebody from your side needs to stand on that floor before award.