Running a Technical Clarification Round Before You Shortlist a Display Supplier

A long list of display suppliers usually narrows on signals that are easy to produce: a catalogue, a fast reply, a believable price band. None of them show whether the supplier can explain its own process once the drawing stops being generic. A display supplier technical clarification round is the cheapest engineering test available before tooling, samples or a purchase order exist.

The round is short by design: six written questions, one annotated drawing, a fixed window, and a comparison record that outlives the people who built it. Run it well and it produces a shortlist. Run it loosely and it produces three months of correspondence and a favourite supplier chosen on tone of voice.

Why the shortlist is decided by the second question, not the first

The first reply is prepared; the second one is not.

Suppliers rehearse the standard questions. The follow-up you send after reading their answer is the first one they cannot have written in advance.

When a technical enquiry goes out, most suppliers reply within a working day, using a datasheet, a standard quality paragraph and a price band. That shows responsiveness and organisation, but not whether anyone there can reason about your part.

The second question changes the test. It refers back to something the supplier wrote and asks for the reasoning: how the figure was measured, what happens at the edge of the process window, who signs a deviation. No answer bank covers that, and one paragraph shows whether the reply is specific.

So the shortlist settles on the second exchange rather than the first. A supplier that checks with an engineer before answering still beats one that answers instantly with an unsupported number. Responsiveness is common; a supplier that can explain its own numbers is not.

The clarification pack: six questions that separate capable from nearby

Six technical questions for an LCD supplier are enough for one round. They ask about process rather than product, so none can be answered by forwarding a catalogue, and each has a recognisable strong and weak form. Send them numbered, with a deadline.

• Which parameter is hardest for you to hold, and why? Look for one parameter and the mechanism behind it, such as tooling alignment or FPC bonding.
• Where does your process window end for the tightest tolerance? Look for a number and the method behind it.
• What would you change to make this drawing more buildable? This separates suppliers who read drawings from those who price them.
• Which inspection step would you add, and at what stage? Accept a named station and a sampling logic.
• What has failed on a comparable build, and what changed? A specific failure is worth more than a clean record.
• Who signs a deviation, and against which revision? Expect a role, not a department.

Suppliers in automotive programmes often answer the last two fluently; AIAG publishes the quality planning references behind them.

Asking for an evaluation drawing before a quotation

An evaluation drawing is not a design. It is your drawing returned with the supplier's annotations: which tolerances are achievable as drawn, where a note is needed, where the measurement method must be agreed, and which features drive cost. Asking for it before a quotation shows whether the supplier has an engineering function that can touch a drawing at all.

Keep the request narrow so it stays a test rather than a project. Send one revision, ask for annotations only, and state that no redesign is expected. Annotation is a review of your intent; redesign is new work that belongs in a separate engineering step, with its own scope and commercial terms.

The response is diagnostic either way. A supplier that returns the drawing with six marked notes and two questions has done the work. One that returns a quotation with a cover letter has not, and the round has told you that before samples are involved.

Which tolerances a supplier must be able to explain unaided

Outline, viewing and electrical, plus the life figure.

Each has a method behind it, and a supplier that cannot name the method has repeated a datasheet rather than explained a limit your team can hold it to.

Outline tolerances cover the mechanical interface: overall dimensions, bezel and active area alignment, mounting features, and FPC tail position. They are simple to discuss and expensive to get wrong, because they propagate into the enclosure.

Viewing tolerances are directional. Contrast and colour shift are stated at an angle, so the angle needs a reference: measured from normal, at a stated luminance, with a stated pattern.

Electrical tolerances are a window, not a point: voltage range, current at a stated pattern, and how both move with temperature. Life is the vaguest, because the figure depends on drive current and duty cycle.

For all four, ask which standard the measurement follows. The ISO standards portal covers the vocabulary most suppliers share, and EU-bound displays also answer to power and lifetime figures under the ecodesign requirements for electronic displays.

Reading the answer for engineering depth rather than sales fluency

Sales fluency has a rhythm: quick reply, warm tone, confident adjectives, a promise to support whatever the project needs. Engineering depth sounds different: a narrower answer, a condition, a number, a question back. Both look like cooperation, so the round needs a reading method that does not depend on how the meeting felt.

Four signals are reliable. Measurement conditions come first, because a figure with a method attached can be checked. Ownership comes second: an answer naming the role responsible tells you who will be asked to honour it later. Admitted limits come third, since a supplier that says where its process stops is describing a real window. A follow-up question comes fourth, and it shows the drawing was read rather than the email.

Length is not a signal. Three lines with a number and a method outrank a page of reassurance, and an answer that declines to guess is worth more than one that covers every option.

Managing three suppliers through the same round

Three is the working number: enough for a comparison, few enough to keep the questions identical. Fix the request, the format and the deadline before the first message goes out, then keep the control sheet below open while answers arrive.

Nothing there asks for proprietary process detail. It asks that the same request reaches all three on the same day, so a difference reflects the supplier rather than the question.

Time-boxing the round so it does not become a free design service

A pre-shortlist clarification round without a closing date becomes a free design service. Answers arrive, your team asks follow-ups, the supplier offers to look at a revised drawing, and three weeks later a factory has given engineering time to a project that may never be quoted. The supplier notices, and answers the next round more cautiously.

Time-boxing costs nothing. Set a ten-working-day window, two rounds of written questions and no more, and a date on which answers are compared whether or not every item is closed. Send the schedule with the first question set, so the deadline is a fact of the round.

The rule that keeps it fair is scope. Annotation of your drawing is in scope; redesign is not. If an answer shows the design needs rework, that is a finding for your own engineers, not a reason to extend the round. Treat the exercise as paid in kind: you get comparable answers, the supplier gets a fair view of the project, and neither side owes the other a programme.

Recording answers so the comparison survives a staff change

People leave, and the round leaves with them unless it was written down as it happened. A mailbox is not a record: it holds the reply but not the question, the revision, or the judgement your reviewer made at the time.

Capture the question identifier, the dates sent and received, the revision referenced, the answer quoted in full, the measurement method named, the role of the person who answered, and a one-line assessment from your reviewer. Store it beside the drawing revision, so the next engineer inherits the reasoning and not only the conclusion.

If the programme ships into more than one market, add the destination. Compliance duties attach to the market where the product is placed rather than to the factory, and EU Access2Markets is a practical place to check what applies.

Moving from clarification to a formal RFQ

The RFQ should carry the round's output: the frozen drawing revision, the tolerance notes with their methods, the inspection points proposed, and the open items you accept as open.

This is where the specification sheet matters. The round does not replace it, and an RFQ sent without one invites as many interpretations as there are suppliers. If the sheet is not written yet, write it first: the guide to a custom LCD specification sheet for an RFQ remains the canonical owner.

Commercial and compliance terms travel with the RFQ too: shipping terms under Incoterms 2020, a RoHS declaration, and, for EU-bound product, the obligations introduced by GPSR. Request documents rather than assurances, and use the custom sourcing guide to see where this step sits in the sequence.

Send the RFQ only to the suppliers that survived, with the record attached. If the round changes the outline rather than the supplier, review the custom LCD display range before the drawing is rewritten.

Should the clarification round compare total cost rather than unit price?

Yes. Unit price hides programme risk.

A clarification round is the wrong place to settle price and the right place to find out what the price excludes. Two suppliers quoting the same figure may be quoting different things: one includes tooling amortisation, the other does not; one includes first-article inspection, the other bills it as a service. Until the scopes are separated, the numbers are not comparable.

Ask each supplier to restate its position as a year-one total and a steady-state total, with tooling, inspection, packaging and engineering support shown as separate lines. The comparison then exposes the assumptions rather than the arithmetic. A supplier that resists separating the lines is telling you something about how the programme will be managed once the order is placed.