Outsourcing box build assembly is a common thing nowadays as it’s convenient for many companies to receive a finished product from their CM. The process ranges from a single printed circuit board to a sub-assembly of mechanical components, cables, wires, and their installation into a protective cover or enclosure. It includes electronic, electro-mechanical assembly, final product assembly, and packaging. Testing and software loading are generally included in this form of product realization; hence you can’t afford to deliver anything less than the best.

When outsourcing a box build assembly, you need to consider a variety of things to ensure you place an effective request with your electronics manufacturing services (EMS) provider.



Bill of Materials (BOM)

The Bill of Materials (BOM) makes it easy for your Electronic Manufacturing Services provider to offer you the best quote. You need to include all the essential components you require in your BOM such:

  • The type of materials you require the EMS to source
  • What materials you’ll provide
  • A detailed description of all small components you’ll require, such as bolts, washers, nuts, heat shrinks, and adhesives, among others.

When creating the BOM, it’s important to describe the quantities required despite that many are labeled as consumables. Oversights in seeming simple components can largely affect your box build assembly budget.


It’s advisable to provide 3D CAD models to help with proper visualization of the end product. Use a CAD package to draw the 3D model. If you don’t have the package, you can source a free package online. The free CAD packages you get online have free drawing viewers, which help you convert drawings into box build instructions.

The 3D CAD models need to include all the box build’s key components, including the respective positioning of the components. Also, make sure that the components’ tolerances are clearly indicated to avoid confusion and errors during the box build assembly.


When dealing with electrical systems, you need to provide the EMS provider with the circuit diagrams. The schematics make it easy for the EMS to understand the circuit, eliminating any risks of errors during the box build assembly.

Sample Unit

It’s always wise to provide your manufacturing partner with a sample unit as a point of reference, especially where the schematics are lacking. This makes it easy for the EMS to translate physical activities from precise drawings, ensuring consistency in the box build assembly.



Unit Specifications

The manufacturing partner needs to know your unit’s size and weight to help them handle and store the unit. It also makes it easy for the EMS to handle the shipping of the complete unit. Based on your unit’s specifications, you need to decide how you want to pack and ship the final product.


Once you decide to outsource your box build assembly, ensure your manufacturing partner carries out the necessary regulatory compliance and safety testing. There’re various types of examinations that you can choose to do, including:

  • Electrical testing
  • Functional testing
  • Burn in
  • Regulatory and agency compliance
  • Validation testing

Although it’s necessary to carry out the aforementioned tests, you might also decide to be satisfied with a visual inspection. Always ask your manufacturing partner about the best test to carryout if ever you feel confused.

Bottom Line

Many manufacturers nowadays prefer outsourcing box build assembly as they can rely on third-party assemblers’ experience and expertise. By outsourcing, you are assured that your products meet the required standards and specifications. You also cut the cost incurred in building a self-owned manufacturing plant.

Outsourcing a box build assembly requires that you cooperate with your EMS partner and your customers. Ensure you’re transparent with your manufacturing partner when it comes to information so that you are both on the same page. Observing these requirements ensures you have a healthy relationship with your service provider and happy customers leading to the success of your business.