In the rapidly evolving landscape of Electronics Manufacturing Services (EMS), one of the most critical decisions a Project Manager or Lead Engineer must make is selecting the appropriate assembly model. This choice directly impacts the project's lead time, total cost of ownership, and supply chain resilience.
When it comes to High-Mix Low-Volume (HMLV) production—where complexity is high and precision is non-negotiable—the debate typically centers on two primary models: Full Turnkey and Consigned (Kitted) Assembly.
Understanding the Models
1. Full Turnkey Assembly In a Turnkey model, the EMS provider manages the entire lifecycle of the project. This includes PCB fabrication, component sourcing, assembly, and testing. The manufacturer acts as a single point of responsibility for the entire Bill of Materials (BOM).
2. Consigned (Kitted) Assembly In a Consignment model, the customer provides all or most of the components and the bare printed circuit boards. The manufacturer is responsible solely for the labor of assembly and testing.
Key Comparison Factors
To choose the right model for your specific project, you must evaluate four critical dimensions:
A. Supply Chain Control & Logistics
Turnkey: The manufacturer leverages its global procurement network. For HMLV projects, this is often a major advantage, as professional buyers can consolidate orders and navigate component shortages more effectively than individual firms.
Consigned: This is preferred if you use proprietary or highly specialized components that are already in your inventory. However, it places the logistical burden of kitting, packing, and shipping on your internal team.
B. Administrative Overhead
Turnkey: Reduces administrative "noise." You manage one purchase order and one vendor. The EMS provider handles late deliveries, damaged components, and substitutes.
Consigned: Significant overhead. Your team must track every line item on the BOM. If a single capacitor is missing or damaged during shipping, the production line may stop, leading to costly delays.
C. Accountability and Quality Assurance
Turnkey: Clear accountability. If a board fails due to a component defect or fabrication issue, the manufacturer is responsible for the resolution.
Consigned: Accountability can become "gray." If a defect occurs, disputes may arise over whether the issue was caused by the customer-supplied material or the manufacturer's assembly process.
D. Cost Management
Turnkey: While there is a markup for procurement services, the "Total Cost of Acquisition" is often lower when factoring in saved labor hours, reduced shipping costs, and minimized inventory holding.
Consigned: May appear cheaper on a per-unit labor basis, but hidden costs—such as internal labor for kitting and the risk of production downtime—often negate these savings.
Which Model is Right for You?
Choose Turnkey if:
You are operating in an HMLV environment and need to focus on R&D rather than logistics.
Time-to-market is critical.
You want to minimize the risk of component obsolescence or counterfeit parts through a manufacturer's vetted supply chain.
Choose Consigned if:
Your project involves unique, custom-made, or "long-lead" components you already possess.
You have a massive existing inventory that must be utilized.
The project is in a very early, highly volatile prototyping stage where components change daily.
Conclusion
The transition from traditional PCB manufacturing to a sophisticated EMS partnership requires a strategic approach to assembly. While consignment offers a sense of control over materials, the Full Turnkey model provides the scalability and agility required for modern high-end electronics.
For companies navigating the complexities of mission-critical industries—such as Medical, Telecommunications, and Industrial Automation—partnering with a provider that excels in HMLV (High-Mix Low-Volume) production is essential.
As a premier provider of high-end EMS solutions, PCBCart specializes in managing this complexity for you. By integrating advanced DFM analysis with a robust global procurement network, PCBCart delivers seamless Turnkey services that allow you to focus on innovation while we handle the intricacies of the supply chain. Whether your project demands rigorous compliance or flexible small-batch production, we provide the expertise to bring your vision to life with precision and reliability.
Helpful Resources
• Full Turnkey PCB Assembly
• Consigned PCB Assembly
• Component Sourcing Services
