Design for Manufacture and Assembly (DFMA) is a design methodology that takes into account ease of manufacture and efficiency of assembly. Through methods such as design simplification or fool-proofing (often called “Poka Yoke”), it is possible to manufacture and assemble it more efficiently, within the least amount of time possible leading to reduced cost. DFMA has been applied in sectors such as the design of automotive and consumer products. They often require their workforce to efficiently produce high quality products in large numbers within a shorter timeframe.
DFMA is the combination of two methodologies – Design for Manufacture (DFM), a design methodology used to ease the manufacturing of parts and Design for Assembly (DFA), a design methodology that is implemented to ease the assembly of a product.
According to Eastek International, the importance of DFMA is emphasized by the fact that about 70% of manufacturing costs of a product (cost of materials, processing, and assembly) are determined by design decisions. Production decisions (such as process planning or machine tool selection) are responsible for only 20%, with the remaining 10% being other processes involved. In very simple terms, integrating DFMA into a company’s manufacturing and assembly lines should reduce the cost and difficulty of manufacturing.
General Overview of DFM
DFM involves designing for the ease of manufacture of a product and its components. It is concerned with selecting the most cost-effective materials and processes to be used in a production. DFM also minimizes the complexity of manufacturing operations.
General Overview of DFA
DFA involves designing for a product’s ease of assembly. It is concerned with reducing the product assembly cost and minimizing the number of assembly operations. It assists the design teams in the design of products at a minimum cost, focusing on the number of parts, handling and ease of assembly.
DFM + DFA = DFMA
The two methodologies elaborated above seeks to reduce material, labor and overhead cost. Other than that, both these methodologies also help practitioners to shorten the product development cycle time. This allows a higher output rate within a shorter period of time while ensuring standards and quality requirements are met. Hence, the terminology – “Design for Manufacturing and Assembly” was conceived.
Principles of DFMA
A working example of DFMA
Picture Source: www.eastekinternational.com
DFMA enables industry players to better identify and eliminate waste or inefficiency within a product’s manufacturing and assembly line. This is achieved through several ways, one of it being the minimization of the number of components. This helps in reducing assembly operations and costs while simplifying automation.
Other than that, products are designed for the ease of part-fabrication (cutting, bending, assembling of parts) where the shape of parts is simplified. This will reduce the difficulty of the assembly of a product. The principle of DFMA also guides designers to design parts that are within the process capability while emphasizing parts clarity – where components are designed so that they can be assembled using only one method. This principle reduces the complexity of assembly operations.
Besides that, the implementation of DFMA helps practitioners minimize the usage of flexible components such as parts made of rubber, gaskets, cables and so on. Usage of flexible parts should be limited as handling and assembly becomes generally more difficult if they are used.
Furthermore, DFMA can also be used as a benchmarking tool to study the products of competitors.
Advantages of DFMA
Picture Credits: M. Ham & J. Jeswiet
One of the primary advantages of DFMA is the lower assembly costs. This is achieved by using fewer parts to assemble a product. Fewer parts imply fewer purchases, handling, processing time, assembly difficulty, inventory, equipment, testing, and so on. Other than that, DFMA lessens assembly time by utilizing standard assembly practices such as vertical assembly and self-aligning parts.
DFMA also promises higher product quality and sustainability. Since DFMA emphasizes on automation, quality and efficiency are enhanced. There may be less waste generation in the assembly phase and greater efficiency in logistics. Plus, DFMA also increases reliability by lowering the number of parts, thereby decreasing the chance of failure.
Design for Assembly is concerned with reducing product assembly cost – minimizing number of assembly operations and individual parts tend to be more complex in design. Design for Manufacturing is concerned with reducing overall part production cost – minimizing the complexity of manufacturing operations. Together, the overall objective is to design a product that is as easily and economically manufactured as possible. The implementation of DFMA will be able to enhance the output of high-quality products within a short time frame with minimum cost.
For more information regarding DFMA, you can watch some videos.