Prototype to production is not a single step — it is an ordered sequence of milestones, each of which closes a class of risk before the next one opens. Skipping a milestone or running them in the wrong order is the structural source of most re-quotes and redesigns. This checklist is the ordered sequence, written for motorized products, where the motor milestone comes first because everything else depends on it.
Why this matters
The ordering matters: a tolerance specification written before the tooling method is committed may need to be rewritten after it. A factory quote requested before the motor duty is validated will be built on the factory's assumption about the motor, not your requirement.
The ordering matters: a tolerance specification written before the tooling method is committed may need to be rewritten after it. A factory quote requested before the motor duty is validated will be built on the factory's assumption about the motor, not your requirement. Each milestone below unlocks the next one — running them out of order does not save time, it imports cost.
The prototype proves function. The checklist below proves production readiness. Both are necessary; neither substitutes for the other.
Milestone 1 — Motor duty validated at production conditions
The first production-readiness milestone is motor duty validation: run the assumed motor at production duty (real run time, real load, real thermal environment) and confirm noise, heat, and performance against spec. This milestone gates everything downstream because the motor determines enclosure geometry, cooling path, tooling method feasibility, and BOM cost.
The first production-readiness milestone is motor duty validation: run the assumed motor at production duty (real run time, real load, real thermal environment) and confirm noise, heat, and performance against spec. This milestone gates everything downstream because the motor determines enclosure geometry, cooling path, tooling method feasibility, and BOM cost. A motor that fails duty validation at Milestone 1 requires a redesign before any subsequent milestone can be closed.
Milestone 2 — BOM locked with production-grade callouts
The BOM lock milestone requires that every line item names a production-grade part with a manufacturer number or grade callout — not 'motor from Alibaba' or 'adhesive for now'. This includes a second-source option or a single-source risk flag for the motor.
The BOM lock milestone requires that every line item names a production-grade part with a manufacturer number or grade callout — not 'motor from Alibaba' or 'adhesive for now'. This includes a second-source option or a single-source risk flag for the motor. The BOM is not locked until a stranger could order all the parts from it without calling you.
Milestone 3 — Tooling method committed and design reviewed
At the tooling method commit milestone, the production tooling method is named — injection mold, die cast, stamped metal — and the design is reviewed against that method's constraints. Draft angles, minimum wall thickness, gate placement, and enclosure parting line are confirmed.
At the tooling method commit milestone, the production tooling method is named — injection mold, die cast, stamped metal — and the design is reviewed against that method's constraints. Draft angles, minimum wall thickness, gate placement, and enclosure parting line are confirmed. This milestone gates the drawing package: you cannot write a production drawing until the tooling method is committed.
Milestone 4 — Tolerances and materials production-specified
After the tooling method is committed, tolerances and materials are specified on drawings that a stranger could read. Not 'tight tolerance' but actual dimension tolerances in the units and format the factory will use. Not 'food-safe plastic' but the specific grade and its certification mark.
After the tooling method is committed, tolerances and materials are specified on drawings that a stranger could read. Not 'tight tolerance' but actual dimension tolerances in the units and format the factory will use. Not 'food-safe plastic' but the specific grade and its certification mark. This milestone gates the RFQ package.
Milestone 5 — RFQ package complete and reviewed
The RFQ package milestone requires that the full package — motor spec, BOM, drawings, volume, target price, timeline, certification requirements, and open questions — is complete and reviewed by someone who has read a real factory quote before. A package that passes this milestone is quote-ready; one that does not should not go to a factory until it does.
The RFQ package milestone requires that the full package — motor spec, BOM, drawings, volume, target price, timeline, certification requirements, and open questions — is complete and reviewed by someone who has read a real factory quote before. A package that passes this milestone is quote-ready; one that does not should not go to a factory until it does.
Decision rule: Do not advance past a milestone until it is closed. A milestone is closed when its outputs — not its activities — are complete. 'We tested the motor' is an activity; 'motor duty validated, noise and thermal within spec, result documented' is a closed milestone.
The ordered prototype-to-production milestones
- M1: Motor tested at production duty — run time, load, noise measured, thermal confirmed against spec
- M1: Motor duty validation result documented — pass continues; fail triggers redesign before M2
- M2: BOM complete with manufacturer part numbers or grade callouts for every line item
- M2: Second-source motor option in BOM or single-source risk flagged in writing
- M3: Tooling method named (injection, die-cast, stamped) and design reviewed against that method
- M3: Draft angles, wall thickness, and gate placement confirmed for the named tooling method
- M4: Tolerances specified on drawings in production-usable format — dimensions and tolerance values, not qualitative descriptions
- M4: Materials specified by grade with certification marks where required (food contact, skin contact, electrical insulation)
- M5: RFQ package complete: motor spec, BOM, drawings, volume, target price, timeline, certifications, open questions
- M5: Package reviewed by someone who has read a real factory quote — not the designer who assembled it
Common mistakes
Running milestones out of order — specifying tolerances before the tooling method is committed. Treating M1 (motor duty validation) as a demo run — running the motor for 30 seconds and calling it validated. Locking the BOM with 'the motor we tested' instead of a manufacturer part number and duty spec.
- Running milestones out of order — specifying tolerances before the tooling method is committed.
- Treating M1 (motor duty validation) as a demo run — running the motor for 30 seconds and calling it validated.
- Locking the BOM with 'the motor we tested' instead of a manufacturer part number and duty spec.
- Sending the RFQ package without an M5 review — the designer is the worst reviewer of their own package.
Frequently asked questions
- Why this matters?
- The ordering matters: a tolerance specification written before the tooling method is committed may need to be rewritten after it. A factory quote requested before the motor duty is validated will be built on the factory's assumption about the motor, not your requirement.
- What is milestone 1 — motor duty validated at production conditions?
- The first production-readiness milestone is motor duty validation: run the assumed motor at production duty (real run time, real load, real thermal environment) and confirm noise, heat, and performance against spec. This milestone gates everything downstream because the motor determines enclosure geometry, cooling path, tooling method feasibility, and BOM cost.
- What is milestone 2 — bom locked with production-grade callouts?
- The BOM lock milestone requires that every line item names a production-grade part with a manufacturer number or grade callout — not 'motor from Alibaba' or 'adhesive for now'. This includes a second-source option or a single-source risk flag for the motor.
- What is milestone 3 — tooling method committed and design reviewed?
- At the tooling method commit milestone, the production tooling method is named — injection mold, die cast, stamped metal — and the design is reviewed against that method's constraints. Draft angles, minimum wall thickness, gate placement, and enclosure parting line are confirmed.
- What is milestone 4 — tolerances and materials production-specified?
- After the tooling method is committed, tolerances and materials are specified on drawings that a stranger could read. Not 'tight tolerance' but actual dimension tolerances in the units and format the factory will use. Not 'food-safe plastic' but the specific grade and its certification mark.
This guide is educational. It is not a manufacturing quote, certification review, legal advice, or a guarantee that a product can be built. If you want this applied to your specific product, request a human-reviewed Motor Readiness Scorecard.
Want this applied to your product?
Request a Motor Readiness Scorecard for a human-reviewed read, or start with a short, no-cost quote-readiness screen.