Iscar Metals
DFMA UP TO DATE

DFMA—Design for Manufacture and Assembly—has been around for a long time.

DFMA—Design for Manufacture and Assembly—has been around for a long time. As Geoffrey Boothroyd wrote in a paper on the subject back in 1999, the Design for Assembly portion was first developed back in the 1960s, then, “In the mid-seventies the U.S. National Science Foundation (NSF) awarded a substantial grant to extend this approach for the general areas of design for manufacture (DFM) and design for assembly (DFA). Essentially, this meant classifying product design features that significantly affect assembly times and manufacturing costs and to quantify these effects.” While someone might therefore imagine that DFMA is, well, old-school, consider the three points that Boothroyd described in that paper as the purpose of the process:

  1. “As the basis for concurrent engineering studies to provide guidance to the design team in simplifying the product structure, reduce manufacturing and assembly costs and to quantify the improvements.
  2. “As a benchmarking tool to study competitors’ products and quantify manufacturing and assembly difficulties.
  3. “As a should-cost tool to help negotiate suppliers contracts.”

So it is about reducing costs, benchmarking, and helping price components. Are the requirements any different today than back in ’99 when Boothroyd itemized those activities?

What is absolutely up-to-date is a new DFMA software package from Boothroyd Dewhurst, Inc. (Wakefield, RI; www.dfma.com), DFMA 2006. The software contains early cost models for various manufacturing processes, including sheet metalworking, machining, structural foam molding, plastic extrusion, injection molding, thermoforming, blow molding, cold and hot diecasting, hot forging, powder metal processing, sand casting, investment casting, printed circuit board processing, and automatic assembly. An interesting aspect of the automatic assembly element of the package is that it allows comparision of costs between automatic and manual assembly, which can be an important consideration for those considering off-shoring of production operations.