Design for Assembly is a design method for a product with the ease of assembly using less parts in the product.
Design for Disassembly is a design process that allows for the easy recovery of products, parts and materials for reuse.
In recent years both DFA and DFD have received a lot of attention due to the increasing importance of longer lasting products, recycling and reusing. Both of these concepts have similar goals, and both of the concepts are cost saving. Design for Disassembly is focussed on the afterlife and on recycling and reusing. DFD can be implemented in products such as electronics; it can also be used as a design process for housing and construction work. On the other side, Design for Assembly is being used on a smaller scale for smaller objects and products and is focussed mainly on the reduction of parts.
You might also come across Design for Manufacturing (DFM); the main difference is that DFM is focussed on the reduction of overall part production. DFA and DFM are considered two different concepts but have become a singular philosophy in recent years, also known as Design for Manufacturing and Assembly (DFMA). DFMA is a methodology with the focus on simplifying the design of an object, by which manufacturing the object becomes easy and efficient. And in return, you might have guessed it already; it is cost saving! And when it becomes cost saving, it becomes attractive for the industry to implement this concept and philosophy, which in turn results in improved sustainability in everyday objects.
When we talk about the methodology and technology for remanufacturing, we need to consider not only the disassembly of products but also the need for re-assembly. Both aspects need to be considered during the design. Remanufacturing has become a very important aspect of environmental sustainability. The main goal is to bring a product or part back to its useful life.