From DDL Wiki

Design for manufacturing and assembly (also called DFM, DFA, or together DFMA) refers to the set of tools, methods and processes for analyzing the manufacturing consequences of design considerations and improving a design in order to reduce manufacturing cost and complexity.

Links

• DRM Associates has a nice page on DFMA here: http://www.npd-solutions.com/dfmguidelines.html
• Boothroyd and Dewhurst (who have written a number of books on DFMA) also sell software to support it: http://www.dfma.com/