DFMA Design for Manufacturing and Assembly
What is DFMA?
DFMA is an abbreviation for "Design for Manufacturing and Assembly" or "Design for Manufacturability and Assembly. It a system comprised of various principles that, when used properly, will improve the ability for a design to be easily manufactured and assembled. It is most benificial to consider these principles during the design phase of new product development. This system can be divided into three major sections. The first is the raw material. Choosing the right material is the foundation of a good design. Second is the machines and processes used to work the raw material. The right process is essential for creating finished parts that will meet your design requirements. Third is the assembly of the product. It is during the assembly of the finished product that provides the greatest opportunity to apply DFMA principles. The proper use of DFMA principles will allow one to design a high quality product.
DFMA Raw materials
Choosing the best raw material for the design is the first step in using DFMA to design a world class product. There are many factors that need to be considered when choosing the best material for a design. First the material must have the correct mechanical and chemical properties to meet the design criteria. Second when possible one should choose a standard material that is readily available. Using special materials may increase purchase price and lengthen deliveries. Third use near net parts whenever possible. The raw material's profile should be as close to finished parts as possible to reduce processing.
DFMA Machines and processes
Choosing the appropriate machine and processes can drastically reduce the time and further increase the quality of the parts. When determining the best machine for the job, there are many things to consider. First and foremost is the material being processed. Some materials may require coolant and others may require special fixturing or tooling. Second is to apply as liberal tolerances as the design will allow. It typically takes longer and is more costly to hold tighter tolerances. Third is the machines capabilities. Pick a machine and process that can provide desired finish, hold tolerances required, and be repeatable. Next is the tooling. You will need to pick tooling with the best combination of finish, performance, life and cost. Another consideration is fixturing. Proper fixturing is necessary for quality while fixturing that is user friendly can reduce the amount of labor time in the manufacturing process.
Assemblies is the area with the most potential in applying DFMA principles. First you can reduce the parts count in an assembly. You can reduce parts by eliminating or combining multiple parts. Second by making parts symmetrical when the design allows. Having asymmetrical parts require more attention in the positioning of the parts at assembly. Third is simplicity of design. Typically the simpler the design the less opportunity for mistakes. Also referred to as the kiss principle. Next is self fixturing. The usage of the part itself to help position or align itself with a mating part. Whenever possible try to avoid using parts in your design that are easily tangled. Tangled parts take time to untangle that may be spent doing productive work. You will also have to think about accessibility. If a part is hard to get to it may take more time to position and assemble it. Last but surely not least is poka yoke or mistake proofing. The goal of poka yoke is to make it impossible to make a mistake.
Design books on Amazon
DFMA books on Amazon
Additional DFMA resources
- 2011 International forum on Design for Manufacture and Assembly
The 26th annual forum is a great educational resource for those who would like to develop a better understanding of DFMA, it's principles and how to apply it. It will also be a great opportunity to network with the industry's leaders on the subject.
- Boothroyd Dewhurst, Inc. DFMA software solutions
Innovators in the development of DFMA software solutions. The DFM software quickly uses what if scenarios for process and material selection. The DFA software is used to reduce complexity and consolidate parts for costs savings
- Lean.org - Lean Enterprise Institute
Our global mission is to be the leading lean educators for society in maximizing value and minimizing waste. To accomplish this goal, we develop and advance lean principles, tools, and techniques designed to enable positive change.
DFMA software basics
- Kanban, a lean production and inventory control method
Kanban is a Japanese word meaning billboard or signboard. A kanban can be used as a signal that something needs to be done, from purchasing inventory to starting production to replenish stock....
- Lean Terminology
This hub gives detailed description of often misunderstood lean terminology including DFMA and many more
- Mistake proofing, applying poka yoke principles
This hub goes in more detail about what a Poka Yoke is, the different types, and applications. Poka Yoke is a DFMA principle used to eliminate mistakes