Product designs are often developed with little
consideration of manufacturing and assembly requirements. Typically, design
deficiencies are not identified until a product is in the manufacturing stage of
the development process. Major design changes are often required to complete
production, which results in schedule delays and increased development costs.
Companies have begun using the Design for Manufacture/Assembly (DFMA) technique
as a tool to optimize the product development process and alleviate this
The DFMA concept emphasizes obtaining the proper
balance between design objectives, manufacturing and assembly requirements,
and process capabilities to decrease product development cycles and costs.
Because more than half of the total cost associated with product development
can be attributed to design decisions made early in the development process, a
key component of DFMA is to integrate the development of manufacturing and
assembly requirements into the design phase. To meet this objective, this
technique facilitates having the design and manufacturing teams working
together (see Appendix
Product Team) to define design goals. Therefore, any problems related to
manufacturing and assembly can be detected early, and the design can be
corrected before being finalized. Also, the need for any new manufacturing or
assembly processes can be identified early, and, if necessary, process maturity
efforts can be incorporated into the overall schedule, thereby avoiding
unnecessary delays to production. Use of this technique throughout the product
development cycle results in less complex, higher quality parts that can be
produced at a lower cost.
The primary objective of DFMA is to simplify product
design, which, in turn, simplifies the manufacturing and assembly processes
required for production. Following are examples of the DFMA guidelines that can
be used to simplify product design:
- Minimize the number of parts necessary to provide the required level of performance and model variations.
- Give careful consideration to existing process capabilities and avoid unnecessary processing requirements when developing designs. Developing a new process can substantially increase overall product development costs and schedule.
- Design parts so that assembly is straightforward and manual intervention is only value-added.
- Minimize the use of flexible parts such as belts, gaskets, and cables. The flexibility of these types of components makes handling and assembly more difficult and increases the part's susceptibility to damage.
- Minimize the use of threaded fasteners, which are time consuming to assemble and difficult to automate. The use of snap-together-fit and other joining techniques improves the efficiency of manufacturing, assembly, and disassembly.
- Incorporate modularity into product design. Modularity reduces the number of parts required and improves the overall quality of the final product.
- Consider automated production of parts.
The DFMA technique optimizes product development by
providing a formal process for simultaneously defining and analyzing design
goals along with manufacturing and assembly requirements. Integrating these
functions results in a product design that can be efficiently manufactured and
assembled to produce a product that meets the customer's needs. Other benefits
to be gained from implementing this technique include reduced production time,
improved product quality, and a lower total life-cycle cost.
Boothroyd, G., Dewhurst, P., & Knight, W. (1994). Product Design for Manufacture and Assembly. New York: Marcel Dekker.
Bralla, J. G. (1998). Design for Manufacturability Handbook. New York: McGraw-Hill Companies.
Lotter, B. (1989). Manufacturing Assembly Handbook. Woburn, MA: Butterworth-Heinemann.
Magrah, E. (1997). Integrated Product and Process Design and Development: The Product Realization Process. New York: CRC Press.
Redford, A., & Chal, J. (1995). Design for Assembly: Principles and Practice. New York: McGraw-Hill Companies.
DRM Associates. The Product Development Forum. 2613 Via Olivera, Palos Verdes, CA 90274. Telephone (310) 377-5569, Fax (310) 377-1315, E-mail: email@example.com.