Design for Manufacturing and Assembly

What is Design for manufacturing in the context of mechanical design engineering?

In product development, mechanical design cannot be done in isolation without involvement of manufacturing. If the design is a multi – part assembly, then considerations for its manufacture and assembly become important for the cost of making them in mass manufacturing.

Generally "to manufacture" refers to the manufacturing of the individual component parts of a product or assemble and that "to assemble“ refers to the addition or joining of parts to form the completed product.

DFMA is a deliberate practice by design engineers to make designs easier to manufacture and assemble

It is a highly practical subject which involves good amount of knowledge in design, manufacturing process, Process capabilities, assembly methods and even operations of the plant.

Relation between DFMA and material /process selection

DFMA studies and practice are closely related to the type of process and material which has been selected for product design.  They vary a lot between process to process.

For example: the approach to design for machined part can be very much different to approach to design for sheet metal fabrication. Also, the considerations to assemble a welded assembly maybe different from considerations to bolt two parts together.

Manufacturing costs

With the main aim of DFMA being to optimize design for manufacturing and ultimately reduce the cost. It important to know the types of costs associated with product design and development in manufacturing

How is DFMA practiced?

It is a cross functional effort which involves design engineers, manufacturing engineers and also allied teams like costing and operations.

In a large organization its more of a complete project effort rather than an individual working on an individual aspect of the design.

Part reduction:

One of the major first steps to reduce assembly costs in any product is to reduce the number of parts. Any reduction in the number of parts in an assembly produces a snowball effect on cost reduction

Integrating DFMA in the design process of the engineer

The design engineer is the primary decision maker in this regard. As he/she has to balance the aspects of functional design vs manufacturability vs durability.

Generally, the designer follows specific guidelines during the design process

  1. Design guidelines for the specific process – Moulding, casting, forming
  2. Design guidelines for Easier part handling
  3. Design guidelines for easier Part insertion and fastening



Categories: DFM