Design for Assembly

By Malcolm Scott

Designing for the Assembly is designing with the assembly process in mind.

That includes how to cut cost, parts, and maximize the efficiency of how it is produced.

Design for Assembly

The first design for assembly method was by Hitachi called the Assembly Evaluation Method.

Based on a “One motion for one part” philosophy during assembly. If more complicated motions was required a point loss system was used.

Ease of assembly was evaluated on how many points were lost.

Origins

The original Design for Assembly method was developed by Geoff Boothroyd.

It could be used to estimate the time to manually assemble a product, and the the cost to have it automatically assembled.

Through this method it was realized that the key to reduce cost came through reducing the number of parts.

Origins (continued)

With it’s criteria, DFA could determine the quality of a design based on assembly vantage point.

Also determine which parts could be theoretically eliminated or combined with other parts.

It’s the most widely used method for assembly efficiency and has had the greatest industrial impact.

Benefits of DFA

Sony’s Walkman: uses Sony’s SMART design.

SWATCH watches. Both designed for fully automated

assembly. Walkman was designed for “vertical assembly”.

Example of Products