What is the difference between turnkey and consignment assembly

When a hardware team is ready to move a circuit board design from CAD files to physical production, one of the first decisions is who sources the components. This choice — between turnkey and consignment assembly — defines the relationship between the original equipment manufacturer (OEM) and the electronic contract manufacturer (ECM), determines who carries procurement risk, and ultimately affects cost, lead time, and product quality. Both models result in a populated circuit board, but the path to get there, and the distribution of responsibility along the way, are fundamentally different.

In consignment assembly, sometimes called kitted assembly, the customer takes full responsibility for the supply chain. The OEM purchases bare boards, sources every component listed on the bill of materials (BOM), and ships a complete kit to the contract manufacturer. The manufacturer's role is limited to the physical assembly process: applying solder paste, running boards through pick-and-place machines, reflow soldering, through-hole welding, and performing inspections.

In full turnkey assembly, the contract manufacturer handles the entire supply chain. The customer provides design files — Gerbers, BOM, and assembly drawings — and the manufacturer takes care of the rest. The manufacturer procures bare boards from a trusted fabrication house, sources all components from authorized distributors, performs the physical assembly, and conducts quality testing. The OEM receives a finished, ready-to-use product.

Many manufacturers also offer a partial turnkey, or mixed, model. In this arrangement, the customer consigns a few specialized, proprietary, or expensive components — such as custom ICs or high-value semiconductors — while the manufacturer sources the remaining standard components like resistors, capacitors, and common logic chips. This approach balances control with convenience, letting the OEM leverage direct vendor relationships for strategic parts while offloading the procurement burden for commodity components.

Selecting the right model is not about finding the universally correct answer — it depends on the specific circumstances of each project. The following factors are the ones that most often tip the decision in one direction or the other.

Production volume and stage. For prototype runs and new product introductions, turnkey assembly is often the practical choice. The manufacturer can move quickly from design files to finished boards without waiting for the OEM to source and ship components. For medium and large production volumes, the decision becomes more nuanced. Companies with established procurement teams and strong distributor relationships may find consignment cost-effective at scale, while those prioritizing speed and simplicity may still prefer turnkey.

BOM complexity. A simple BOM with common, readily available components lends itself to either model. A complex BOM with dozens of line items, long-lead-time parts, and specialized components tilts the balance toward turnkey, where the manufacturer's procurement team can manage the complexity and flag sourcing risks early through BOM scrubbing and DFM review.

In-house procurement capability. If the OEM has a dedicated procurement staff with existing distributor accounts and inventory management systems, consignment may be viable. Teams without these resources — particularly startups and small hardware companies — benefit from the turnkey model, where the manufacturer absorbs the procurement workload.

Industry compliance requirements. For medical devices, automotive electronics, and other regulated industries, traceability is not optional. ISO 13485 for medical devices and IATF 16949 for automotive both require documented component traceability. In a consignment model, the OEM must maintain this documentation themselves. In a turnkey model, the manufacturer's quality management system handles traceability as part of standard procedure, sourcing from authorized distributors and maintaining lot-level records.

The choice between turnkey and consignment has implications beyond logistics. For products destined for regulated markets, every component must be traceable back to its source. Counterfeit components — a real risk when sourcing from unauthorized channels — can cause field failures, regulatory violations, and costly recalls.

A manufacturer operating under ISO 9001, ISO 13485, or IATF 16949 quality management systems is required to source from authorized distributors, perform incoming component inspections, and maintain documentation for full traceability. This is why many OEMs in medical, automotive, and industrial sectors prefer the turnkey model: it places the compliance burden on a certified partner rather than spreading it across the OEM's internal team.

Farway Electronic, based in LongGang, Shenzhen, operates as a one-stop electronics manufacturing services provider capable of supporting both turnkey and consignment assembly. The company's service chain spans PCB fabrication, component procurement and management, SMT assembly, DIP through-hole welding, PCBA OEM manufacturing, conformal coating, low-pressure injection moulding, PCBA testing, and finished-product box-build assembly.

For turnkey projects, Farway's component management team works with authorized brand agents and distributors, checks customer BOMs for sourcing risks, and uses ERP-controlled warehousing with first-in-first-out inventory, anti-static storage, and vacuum packaging to manage materials. Before assembly begins, engineering teams can conduct DFX reviews and BOM scrubbing through the company's value-added NPI and DFX services. On the production floor, Yamaha placement machines handle SMT assembly with capability down to 01005 components and 0.2 mm BGA pitch, while Nitto wave-soldering equipment supports DIP through-hole welding.

Quality verification covers SPI solder-paste inspection, AOI optical inspection, X-ray inspection, ICT circuit testing, FCT functional testing, and thermal imaging — aligned with IPC-A-600H for PCB fabrication and IPC-A-610 for PCBA assembly standards. The company holds ISO 9001, ISO 13485, IATF 16949, and ISO 14001 certifications, making it suitable for projects in medical, automotive, new energy, security, and communications industries.

For customers who prefer consignment, Farway's turnkey smt pcb assembly service can be scaled back to assembly-only, with the manufacturer providing SMT, DIP, coating, and testing while the customer supplies components. The same flexibility applies to oem pcba manufacturing, where Farway can work with customer-supplied kits or handle full procurement depending on the project requirements. And for projects that need to go beyond bare board assembly, Farway also serves as a turnkey finished product assembly supplier, integrating tested PCBA boards with enclosures, wiring harnesses, and human-machine interfaces into complete packaged products.

In consignment assembly, the customer purchases all components and ships them to the manufacturer, who provides only the assembly labor. In turnkey assembly, the manufacturer handles everything: sourcing bare boards, purchasing components, performing assembly, and conducting testing.

The upfront quote for turnkey is higher because it includes component and board costs. However, when factoring in the internal labor of procurement, shipping costs, and the risk of production delays from component shortages, turnkey is often more cost-effective overall, especially for teams without dedicated procurement resources.

Partial turnkey is a hybrid model where the customer supplies certain proprietary or hard-to-find components, while the manufacturer sources standard components and performs the assembly. It combines the cost advantages of direct sourcing for strategic parts with the convenience of manufacturer-managed procurement for commodity components.

Medical devices, automotive electronics, and industrial controls — industries with strict traceability and compliance requirements — benefit most from turnkey, as the manufacturer's certified quality system handles component sourcing, inspection, and documentation.

Yes, but it requires reconciling any unmatched inventory and transferring procurement responsibility. It is generally easier to decide the sourcing model at the quotation stage rather than switching mid-production.

The decision between turnkey and consignment assembly is not a question of which model is universally better — it depends on your team's capabilities, your BOM complexity, your production volume, and your industry's compliance requirements. For OEMs that need speed, simplicity, and a single point of accountability, turnkey is the natural choice. For those with established procurement infrastructure and specialized component requirements, consignment offers control and cost transparency. And for many projects, partial turnkey provides the best of both worlds.

The key is to evaluate your situation honestly: do you have the procurement bandwidth to manage a complex BOM? Do your components require specialized sourcing? Are you in a regulated industry where traceability is mandatory? Answering these questions will point you toward the model that fits your project, your timeline, and your budget.