What Is OEM Manufacturing? Everything You Need to Know

An original equipment manufacturer (OEM) is a company that makes a product to another company’s design and specification, which that company then sells under its own brand. OEM manufacturing is that arrangement: the brand owns the design and the intellectual property, and the manufacturer supplies the factory, the processes, the workforce and the quality control needed to build it.

The term has a second, older use. In the car and computer industries, “OEM” also refers to the brand that sells the finished product, and an “OEM part” is one made by or for that brand rather than by an aftermarket supplier. Both uses rest on the same idea: the original design belongs to the brand. This guide covers OEM manufacturing in the first sense, the one that applies when you commission a factory to build your product.

What does an original equipment manufacturer do?

OEM manufacturers range from a factory that makes one component to a partner that delivers finished, packed products. A full-service OEM manufacturing project usually covers:

• Design review. Checking the design for manufacture and assembly (DFM and DFA) before money is spent on tooling.
• Tooling. Specifying and validating the moulds, dies and fixtures that are made for your product alone.
• Component sourcing. Buying parts and materials to your bill of materials (BOM) from qualified suppliers.
• Fabrication. Processes such as injection moulding, CNC machining, sheet metal work and PCB assembly.
• Assembly and testing. Building each unit to documented work instructions and testing it against your specification.
• Quality control and packing. Inspecting incoming parts, checking during production, inspecting before shipment and packing to your retail or shipping specification.

OEM component manufacturing services sit at the narrow end. A factory makes a fabricated part, such as a machined housing or a moulded bezel, to your drawing, and ships it to the plant that assembles the finished product.

How OEM manufacturing works, step by step

• Brief and quotation. You share drawings or CAD files, the BOM, target volumes, target cost and timeline. A credible quote separates tooling from unit price.
• DFM review. The manufacturer’s engineers flag features that will be expensive or unreliable at volume, such as undercuts, tight tolerances that do not need to be tight, or fasteners that could be removed.
• Prototypes and samples. Units are built to test fit, function and appearance. You approve a sample before tooling is cut.
• Tooling and first article inspection. Production tools are made and trialled, and parts from them are measured against the drawing line by line.
• Pilot run. A small batch proves the line, the work instructions and the test process before full volume.
• Mass production. Production runs with inspection at each stage and a final inspection before goods leave the factory.
• Packing and shipping. Goods are packed, labelled and either shipped or held in a warehouse for later release.

OEM vs ODM vs contract manufacturing

These terms are often used loosely by factories, so it is worth confirming which one a supplier means.

• OEM. The factory builds your own design as a new product. You own the design, and the product is unique to your brand.
• ODM. An original design manufacturer takes an existing, production-proven design from its range and puts your label on it. It is quicker to market and needs less development, but you do not own the design and competitors can sell the same product.
• Contract manufacturing. The umbrella term for making products for another business. Most contract manufacturing for brands is OEM work. See what a contract manufacturer is.

The choice between the two models is covered in more detail in OEM vs ODM manufacturing.

OEM parts vs aftermarket parts

In repair and replacement, an OEM part is one made by the original brand, or by its supplier to the brand’s specification. An aftermarket part is made by a third party to fit the same product. Quality ranges from equal to the original to well below it. The same distinction applies to tools, as explained in the guide to OEM tools and tooling. If you commission OEM manufacturing, your product becomes the original, and the parts made for it are your OEM parts.

Advantages and trade-offs of OEM manufacturing

• No factory to build. Capital stays in product development and sales rather than in buildings, machines and a workforce.
• Access to processes and engineers. An established OEM factory already has the toolmakers, test equipment and production engineers your product needs.
• A product that is yours. Unlike ODM, the design, the specification and the improvements made during development belong to you.
• Volume that follows demand. Output can rise or fall without hiring or reducing your own staff.

The trade-offs are real. OEM work carries tooling and development costs before the first unit ships, minimum order quantities, a longer route to market than ODM, and a risk to your intellectual property if the factory or its suppliers can see the full design.

What to put in an OEM manufacturing contract

Most OEM disputes come from points nobody wrote down. Before production, the OEM contract should settle:

• Intellectual property. That the design, drawings and improvements are yours, and that the factory will not make or sell your product for anyone else. For China, this is usually an NNN agreement.
• Tooling ownership. That tools are your property once paid for, with the right to move them.
• Specification and golden sample. The approved drawings, materials and a signed reference sample that production is judged against.
• Acceptance criteria. How goods are inspected, the sampling level (often an AQL plan) and what happens to a failed batch.
• Change control. That no material, component or supplier changes without your written approval.
• Price, MOQ and lead time. Including how price changes for raw materials are handled.

How Shield Works approaches OEM manufacturing

Shield Works is a British-owned, Western-managed OEM manufacturer in Zhuhai, China, and part of the C2W Group. It runs a 100,000 sq ft precision manufacturing and assembly facility certified to ISO 9001, ISO 14001 and ISO 45001. The specifics of working with a factory there are covered in OEM manufacturing in China.

Projects start with the DFX team, which reviews the design for manufacture and assembly and prototypes it before tooling. Shield Works uses qualified suppliers for components and processes outside the facility and stays accountable for the finished product. Each supplier receives only the data it needs for its own part, and sub-assemblies are integrated inside the facility, as set out on how we protect your IP.

Quality is verified in two layers: by Shield Works’ own quality team, and independently by C2W Group quality engineers, who report directly to the client. See quality inspection and testing, and the full scope on the contract manufacturing services page.

If you have a product that needs an OEM manufacturer, submit your project brief with drawings, target volumes and timeline. We review every submission and come back to you if the project is a fit.