How should supplier feedback change the design?
Obeying every note produces a product that is easy for one factory and wrong for the user. Refusing every note produces a tool that fights the process, and a blame argument later. Put the requirement in the same row as the comment so the choice is visible. Figures below are hypothetical teaching maths, not BrahmWorks prices, yields, timelines or test results. Getting that disposition into the files before a repeat build is part of How to Take a Hardware Prototype to Production.
BrahmEarth sensor nodes mounted on a wall
What kind of comment it is
Sort the note before you debate it. A "cannot" is a process limit: the press will not mould that undercut, the line cannot place that package, the sheet size will not blank that flat pattern. Treat a cannot as true until you have a second process that can, not as an opinion to out-argue. A "costly" is a price for a feature you may still want: a slide, a tight bore, a special finish. Costly is allowed to survive if the requirement is real and the price is accepted in writing.
A "cannot" is a process limit: the press will not mould that undercut, the line cannot place that package, the sheet size will not blank that flat pattern.
A "preference" is a habit: gate it here because we always do, add a rib in our house style, change a fastener to the one on their shelf. Preferences can be good. They are not requirements. A "risk" is a warning about warp, a weak boss, a solder joint beside a mounting hole. Risks need a mechanism, not an adjective. "This will be a problem" is not yet feedback you can design with. Ask what fails, under what condition, and how they have seen it fail before.
Lead time and minimum order are design inputs when they make a part unavailable at the quantity you build. They are not a reason to redraw a working interface every time a buyer is impatient. Distinguish "we cannot get this for the pilot" from "this part should not be in the product".
Who is allowed to accept
The supplier owns the process statement. You own the product requirement. A moulder can require a change in order to fill and eject. They do not own the decision to drop a seal, a creepage distance, or a service opening. If their suggested move breaks one of those, the disposition is adapt: keep the requirement, find another geometry, or change the requirement explicitly and tell whoever promised it.
Name a single owner for the disposition list. Comments accepted in a chat, in a marked-up PDF, and in a phone call will disagree. The model then follows whichever file was saved last. The record is a table: comment, requirement affected, disposition, revision. If it is not in the table, it is not accepted, however sensible it sounded on the call.
When two suppliers disagree
A moulder wants a thicker wall. A contract manufacturer wants the same wall thinner so a connector latches. Both can be correct about their own process. The product requirement decides, or you change one of the processes. Averaging the thickness pleases neither and may fail both. Write the conflict as a conflict. Do not send each supplier a private compromise.
Feedback also arrives late because the pack was vague. If you did not mark show faces, you will be asked to accept ejector pins on them. If you did not state a torque, you will be offered whatever the driver is set to. Specific requests get specific notes. An open "please review" gets a review of whatever the supplier finds expensive, which may not be what you find risky.
Worked example: a boss the moulder wants to move
The teaching part is a moulded base for a handheld device. It is not a BrahmWorks product. The moulder returns three notes. Move a boss 4 mm towards a wall so it fills and so the rib is shorter. Increase the nominal wall. Delete a slide by opening a side port into a shut-off that changes the port from a circle to a slot.
The boss move breaks a board keep-out you can measure. That note is adapted, not swallowed: the boss moves 2 mm, the board outline is checked, and the remaining fill concern is answered with a flow rib the moulder agrees to, rather than with the full 4 mm. The wall increase on a non-show area is accepted, because you had no stiffness requirement that the thinner wall was serving, and sink on that face is allowed. The slide deletion is rejected for now. The circular port is a mating connector's requirement. A slot would need a new connector or a new claim that the connector still seals. The moulder has not been given that requirement in the first pack. Add it, and ask for a shut-off that keeps the circle. If none exists, the slide stays and its cost is accepted, or the connector changes in a revision of its own.
The point of the example is the split disposition. One list from a supplier is not one answer.
Labelled calculation: paying for the slide you refused to delete
Hypothetical teaching maths. Not a quote and not a BrahmWorks result.
Assume the slide the moulder offered to delete adds INR 80,000 to the tool. Assume their shut-off alternative is free of tool premium and forces a connector change. Assume the connector change is INR 35 per unit in piece price, against the current connector, at an invented delta, for 2,000 units: 35 × 2,000 = INR 70,000. Tool premium versus piece delta is then 80,000 against 70,000 at that quantity.
At 2,000 units the slide is the dearer path by about INR 10,000, before any tooling change to the mating part and before a seal test. At an assumed 8,000 units the connector delta would be 35 × 8,000 = INR 2,80,000, and the slide is the cheaper path by a wide margin, if the connector change is truly INR 35 forever. The figures are assumptions. The useful act is to put the slide's tool premium next to the requirement it protects, at your quantity. Rejecting the feedback with no sum is stubborn. Accepting it with no check of the connector is obedient. Neither is a disposition.
Checklist for using supplier feedback
- Every note is tagged cannot, costly, preference, risk, or lead time.
- A cannot names the process limit. A risk names the failure.
- The product requirement sits in the same row as the note.
- Disposition is accept, adapt, or reject, with a person and a revision.
- Chat agreements are copied into the table or they do not count.
- Two suppliers who disagree are shown both notes, not two private compromises.
- A late note is checked for a vague pack before it is treated as a new law.
- Accepted geometry is in the model, not only in the reply email.
- Rejected savings have a cost written beside the requirement you kept.
Related questions
Should you accept every comment to protect the schedule?
No. A comment accepted in a hurry can delete a seal, a clearance, or a test point you will spend longer putting back. Sort cannot from preference the same day if you must move quickly. Accept the cannots that are real, and give preferences a revision instead of a same-day edit. Speed without a disposition list is how the model and the tool diverge.
What if you disagree with a "cannot"?
Ask which machine, which material and which rule make it impossible, and whether another supplier's process would differ. A second opinion is legitimate. A second opinion that is really "try harder" is not. If two competent suppliers say the feature will not fill or will not eject, treat the feature as the problem. Changing supplier to escape a geometric limit usually buys the same limit with a new commercial relationship.
Does accepting feedback move responsibility onto the supplier?
Not for the product requirement. The supplier remains responsible for executing the accepted process. You remain responsible for the choice to drop or keep a function. A note that says "customer accepted sink on this face" protects both sides. A note that only says "DFM incorporated" protects neither, and it will be reread after a field failure as if it had been a guarantee.
How do you stop feedback arriving after steel is cut?
Send the requirement pack before the tool is ordered, with show faces, seals, keep-outs and the features you already suspect. Ask for notes against that pack, with a date after which comments are change requests, not free redesigns. You cannot forbid a supplier from learning during the tool build. You can forbid silent geometry. A change after steel is a revision with a cost, even when it is a good change.
Put a disposition on every note
Bring the marked-up file, the requirements the supplier was shown, and the notes you feel pressed to accept. BrahmWorks can help separate a true process limit from a preference that would quietly edit the product.