Design for Assembly

What is design for assembly (DFA)?

The goal of design for assembly (DFA) is to lower product cost by examining a product design in the early stages of development.  Using DFA also leads to improvements in serviceability, reliability, and quality of the end product.  Design for assembly minimizes the total product cost by targeting assembly time, part cost and the assembly process at the design stage of product development cycle.

One aspect of DFA is reducing the number of parts in an assembly.  The DFA methodology for decreasing the number of parts in an assembly by combining several parts into one is based on several questions, such as:

  • Is there a need for relative motion?
  • Is there a need for subsequent adjustment between parts?
  • Is there a need for service or repair?
  • Is there a need for materials to be different?

However, part reduction should not exceed the point of diminishing return, where further part elimination adds cost and complexity because the remaining parts are too heavy, too complicated to make and assembly, or are too unmanageable in other ways.