01
Bridge purpose and horizon
Define why the route exists, intended quantity/rate, duration, service use and commercial or technical assumptions.
Evidence route
Approved bridge charter and demand horizon
Transitional manufacturing control
Bridge production: qualify the temporary route and define how it ends.
Bridge manufacturing can support ramp-up, uncertain demand, tooling lead time, disruption or end-of-life supply. It remains a production route with its own material, process, capacity, inspection and change risks—not an unlimited extension of prototype approval.
Decision premise
Bridge question: which temporary route can supply accepted parts until which measurable migration or stop condition?
Engineering control
Six controls for a safe bridge-production programme
A bridge is controlled by its entry criteria, operating evidence and exit gate. ‘Temporary’ is not an inspection exemption.
02
Route and material delta
Compare bridge and target-production geometry, material, process, finish, tooling and variation characteristic by characteristic.
Evidence route
Delta matrix and authorised use limitations
03
Supplier and capacity
Confirm route-specific capability, equipment, subcontractors, throughput, bottlenecks, maintenance and continuity risks.
Evidence route
Capacity basis, supplier route map and contingency
04
Qualification and control
Set first-off/pilot evidence, CTQ inspection, sample plan, process records and reaction rules at the risk-appropriate level.
Evidence route
Bridge release package and lot control plan
05
Change and genealogy
Keep bridge parts identifiable and control changes in material, programme, equipment, tooling, site or supplier.
Evidence route
Lot genealogy, change log and authorised deviations
06
Migration or stop gate
Define inventory, validation, date, volume, cost, capacity or target-tool conditions that trigger transfer, reapproval or closure.
Evidence route
Exit criteria, transition plan and named decision owner
Decision matrix
Bridge scenario to control emphasis
The appropriate bridge route depends on function, demand and the target production state—not solely on unit price.
| Bridge scenario | Primary control | Exit evidence |
|---|---|---|
| Tooling lead-time gap | Temporary route delta and usable-part criteria | Qualified target tool and inventory transition |
| Demand uncertainty | Volume/cost threshold and configuration stability | Approved scale-up or controlled phase-out |
| Supplier disruption | Rapid capability and material/process equivalence review | Primary route recovery or new-source qualification |
| Pilot market supply | Traceability, feedback and change segregation | Design freeze and production-release decision |
| End-of-life demand | Small-lot control and obsolescence risks | Final-buy/closure approval and record retention |
Claim boundaries
Bridge assumptions that require challenge
Prototype acceptance does not automatically release saleable bridge parts.
A temporary route still needs controlled drawings, materials and inspection.
A bridge supplier’s short-term capacity does not prove sustained rate.
Migration without lot segregation can mix differently qualified product.
Technical context
Use guidance to frame the review—not to replace project evidence.
External context for transitional supply across additive, CNC and rapid tooling routes. PartVerity defines the qualification and exit gate per project.
Protolabs bridge-production guidance