Turnkey vs consigned PCB assembly: choose the responsibilities

Turnkey vs consigned PCB assembly: the practical difference

In turnkey PCB assembly, the assembler typically purchases the agreed boards and components and performs the defined assembly work. In consigned assembly, the customer supplies some or all of that material. Partial turnkey divides purchasing responsibilities between the parties. The useful comparison is who owns each task, which costs are included and how exceptions are resolved.

The sourcing model does not change the product’s electrical function or acceptance requirement. A consigned build still needs controlled files and a verification plan. A turnkey build still needs the design owner to approve substitutions and unresolved requirements. Neither label, by itself, establishes quality, speed or a lower total cost.

This page helps you choose and document responsibilities. For the commercial service scope and how to start a project, use turnkey PCB assembly. Keeping the decision guide separate from that service page makes it easier to compare alternatives without repeating the same sales proposition.

Compare the responsibilities, not just the label

These are discussion patterns rather than standard contractual allocations. An assembler may source the components while the customer supplies a specialized bare board, or the customer may provide one critical IC and ask the assembler to source everything else. Describe the split precisely instead of treating “partial turnkey” as an adequate instruction by itself.

Build a responsibility draft for the quotation

Choose an owner for components, bare boards, alternate approval, receiving, shortages and excess. The planner records unresolved items and describes the purchase allocation. It does not rank suppliers, recommend a contract or treat a completed form as approval. Use the downloadable draft to make the next conversation more concrete.

“Joint agreement” should lead to named decision makers, timing and evidence, not shared ambiguity. In particular, the person purchasing a replacement is not automatically the person authorized to approve its design suitability. Keep engineering authority visible even when the assembler handles the complete procurement process.

When turnkey is a useful starting point

Turnkey can be useful when the customer wants one manufacturing conversation covering boards, components and assembly rather than coordinating separate deliveries. The key input is still a usable BOM with exact identities, approval rules and a stable release. A supplier cannot responsibly solve an undefined requirement merely by taking purchasing responsibility.

Ask how the proposed sources are controlled, how uncertain availability is reported and when purchase commitments require approval. Define the treatment of minimum order quantities, non-cancellable material, excess stock and design changes after purchasing begins. These issues affect both cost and the flexibility to revise the design later.

Turnkey also does not mean every downstream activity is automatically included. Programming, functional-test development, coating, enclosure integration, special packaging and records need an explicit scope. Refer to the PCB assembly cost guide when comparing the included work rather than assuming the purchasing model defines the entire deliverable.

When consigned material can make sense

Consignment can be appropriate when a customer already owns approved inventory, controls a specialized supply agreement or must provide a specific component or board. The benefit depends on whether that material is suitable and ready for the actual process. Existing stock is not automatically cheaper once reconciliation, packing, shortages and unused quantities are considered.

Send exact part identities, quantities and packing information before shipment. Identify the board revision and BOM line represented by each material group. Provide relevant moisture-sensitive handling history and condition information where required. The actual manufacturer’s documentation determines the device requirements; TI packaging resources illustrate the type of source to consult for applicable TI parts.

Agree how incoming material will be counted and checked, how discrepancies are recorded and what happens to unsuitable or unexplained items. A receiving check may confirm labels and visible condition without proving hidden authenticity or long-term device integrity. State the evidence required instead of treating “customer supplied” as an exemption from material control.

Before sending irreplaceable or costly parts, discuss setup allowance, expected use and any shortage contingency. Do not apply an arbitrary percentage from another project. Package type, preparation and process route can change the appropriate plan. Keep installed demand separate from extra supplied material in the assembly BOM.

Make partial turnkey explicit at line level

A mixed build needs a supply-owner field and a clear kit-completion record. Suppose the customer supplies the processor while the assembler purchases passives and connectors. A delayed processor can still hold the build even when the other material is ready. Define who confirms readiness and who authorizes a schedule change when one part of the kit is incomplete.

Use exact reference or part identities for the split. Avoid instructions such as “we will send some ICs” without quantities and revision context. Confirm whether customer-supplied components replace the corresponding procurement lines or supplement them as spares. Otherwise, both parties can purchase the same item while another item is missing.

Resolve cross-boundary changes carefully. If the designer approves a new processor, the decision may affect the customer’s inventory, the assembler’s programmed setup, test firmware and the remaining BOM. Keep the engineering-change process connected to procurement instead of updating only the purchase spreadsheet.

Compare total project cost on the same boundary

A consigned quotation can look lower because it omits components that the customer has already bought. To compare full-project cost, include those purchases and relevant inward logistics, preparation and inventory exposure. If you only need the assembler’s invoice comparison, label that narrower boundary and do not describe it as the total cost of the assembled product.

Separate one-time preparation from recurring work. A fixture can remain necessary whether the assembler or customer bought the parts. Similarly, a missing or inconsistent placement file creates preparation questions under either sourcing model. Use the required-file checklist to compare data readiness without assigning it to the wrong commercial category.

The assembly cost calculator can add your entered allowances once the boundary is agreed. Do not enter zero for consigned components in a full-project comparison simply because their cost is absent from the assembler’s invoice. Identify the date, quantity basis and scope of every allowance.

Lead time begins with a defined readiness condition

Materials, released files, approved exceptions and required tooling must converge before the planned build can proceed. Ask what event starts the quoted production interval. A turnkey buyer waiting for a long-lead component and a consigned buyer waiting for a customer shipment can both face a kit-readiness delay.

For consigned shipments, allow for receiving and reconciliation rather than assuming arrival at the building means production release. For turnkey material, distinguish purchase confirmation from actual availability for the job. Identify shortages and approval holds in a shared action list with owners, not just a single optimistic delivery date.

For repeat builds, agree how retained inventory is identified, counted and checked against the new order. Previous approval does not automatically cover a changed revision, replacement part or altered handling condition. Use the assembly lead-time guide to discuss readiness dependencies and the information needed for a credible schedule.

Resolve the exception rules before they are needed

Document alternate approval, short shipments, material damage, rejected parts, excess disposition and changes after purchasing. Identify who can stop or release the build when an unresolved item affects the product. These are project decisions that should be agreed with the relevant commercial and engineering owners; a generic sourcing label cannot settle them.

The BOM alternative approval guide addresses one common exception. Keep proposed candidates separate from approved replacements and record the scope of approval. A substitute accepted for one prototype lot should not silently become the default for all future production.

To start a review, send your board revision, build quantity, available file package and proposed material split. List any customer-owned stock and open requirements. The PCB assembly team can discuss the build directly; longer-term OEM programs may also need the broader supply and change-control scope of electronic contract manufacturing.

Turnkey and consigned assembly questions