The Design Package

When you’re ready to build, everything hinges on clear, complete documentation. The design package is your product design blueprint to develop the right manufacturing processes.

It ensures that everyone is working from the same playbook (engineering, manufacturing and product). It also freezes the design and locks in what's acceptable and what's not, so future changes can be handled in a controlled and systematic way.

What’s in a Design Package?

• What parts are included

• How to put it together

• How to know if it's acceptable to ship

A strong design package supports alignment across teams, accelerates the quote process, and reduces the time to bring up a repeatable build process on a manufacturing line.

Design Package Contents

PCBAs

• Part numbers

• Indented BOM

• Gerber package

• Fabrication instructions

• Test specifications

• Conformal coating (as required)

• PCBA drawing

Plastics and Metals

• Part numbers

• Custom part specifications

• 2D drawings

• 3D CAD files

• Color / Material / Finish (CMF) requirements

• Material callouts and finishing requirements (especially for metal parts)

Box Build

• Assembly numbers

• Indented BOM (PCBA, metals, plastics, off-the-shelf parts)

• Top-level assembly and component drawings (2D + 3D)

• Test specifications

• Assembly instructions

• Packaging specifications

Functional Requirements Document (FRD)

The FRD defines what is acceptable to ship.

It outlines what the factory (or your internal team) is responsible for assembling, testing, and shipping. It is an important tool to align expectations with the manufacturing team (and partner), and alignment across teams. Get a copy of a Functional Requirements worksheet here.

The Bill of Process

If the Bill of Materials (BOM) outlines the components and subsystems in your product and the Bill of Process (BOP) outlines how to build it.

The Bill of Process outlines the production process for a specific product, including all steps, tools, machines and equipment needed for manufacturing. This also includes all assembly and test instructions for each step, with pass / fail criteria as applicable.

The Bill of Process is not typically part of the design package, it's developed by the manufacturing team (building inhouse) or codeveloped with a manufacturing partner, all using the design package as a guide. Typically there are questions along the way, which will involve your engineering team.

Why is the Bill of Process Necessary?

The bill of process makes manufacturing more consistent, repeatable, and predictable. Without the bill of process, there may be expensive rework at different stages of the manufacturing line (best case), or issues in the field with customers (worst case).

Consider cooking as an analogy - the Bill of Materials (BOM) is your ingredient list, and the Bill of Process is the recipe. 

Pilot Builds

Once your Bill of Process is outlined, and the line has been designed and set up, run pilot builds.

What to track:

• Yield at every stage (component, sub-assembly, finished goods)

• Time per step and total build time

• Defects or issues by step

• Notes from operators or engineers

Why track data?

• Predict future build effort

• Identify root causes of manufacturing issues

• Improve line speed and quality

• Support field failure investigations

Pilot builds uncover issues, across manufacturability, assembly, and test. Be sure the team has an efficient, closed loop process to identify, document and resolve what’s not working. 

Design your line with debugging in mind. A well designed fixture or test equipment will provide visibility into issues early in the assembly process.

In-House Manufacturing vs. Working with a Partner

One of the most critical decisions is how you’ll build. Consider some of the pros / cons in the below image of common manufacturing approaches.