Save costs and avoid errors with design for assembly

Image courtesy of Marin Bikes

Image courtesy of Dynamic Structures Ltd.

What is design for assembly (DFA)?

Designing for automated assembly entails matching components to the manipulation and assembly capabilities of the automation equipment.

The role of DFA in design and manufacturing

Screen shot of gear pump assembly design in Autodesk Fusion interface

The mechanics of design for assembly

Inventor for DFA and DFMA

The Forge office complex in London under construction, design and engineering firm Bryden Wood.

Industrializing net-zero building

Image courtesy of Bryden Wood
Rendering of Hong Kong Advanced Manufacturing Centre.

Assembly design for offsite manufacturing

Screenshot of rules and rails of DfMA presentation.

Rules and rails of DfMA for building products

Modular and off-the-shelf parts

Automated assembly

Design compatibility for automation

Fasteners and assembly speed

Mistake-proofing (Poka-Yoke)

Prototyping and software

Design for assembly (DFA) vs. design for manufacturing and assembly (DFMA)

Planning

Materials

Processes

Standards

Optimizing material selection in design for manufacturing and assembly (DFMA)

What is the design for assembly concept?

The design for assembly (DFA) concept is to make a product’s assembly simpler, faster, less expensive, and error-free—with the simultaneous goal of reducing waste in materials and labor. Designers accomplish this by minimizing the number of parts needed to assemble and making those parts efficient to assemble.

DFA done well can reduce the cost and time of production, as well as reduce material waste, while resulting in products that are more reliable or easier to repair.

What are the principles of DFA?

The principles of DFA are:

  • Reducing the number of components and parts

  • Using off-the-shelf, standard parts

  • Poka-yoke: make the assembly mistake-proof

  • Modular designs save assembly time

  • Symmetrical designs simplify assembly

  • Don’t make tolerances too tight

  • Using built-in fasteners like snap fits

  • Parts are easy to manipulate

  • Parts are self-aligning or self-locating

What is the difference between DFA and DfMA?

Design for assembly (DFA) and design for manufacture and assembly (DfMA) are closely related methods in the larger design for excellence (DFX) philosophy. DFA focuses on optimizing designs for quick and error-free assembly, generally by striving to make simpler and fewer parts.

DfMA combines DFA and design for manufacturing (DFM), in which the design focuses on materials selection and the ease and efficiency of manufacturing processes. DfMA can deliver more reliable products, reduce time to market, and lower costs by producing simpler—yet just as functional—products that are more efficient to manufacture and assemble.