A product architecture-based
conceptual DFA technique
A conceptual design for assembly (DFA) method is introduced in this
paper. The method incorporates DFA analysis into the conceptual design
phase. Current DFA methods, essentially all of which are post-design DFA
analyses, are reviewed with emphasis on the popular Boothroyd and
Dewhurst method. The product architecture-based conceptual DFA method
developed and presented in this article uses two relatively new concepts:
the functional basis and the method of module heuristics. The functional
basis is used to derive a functional model of a product in a standard
language and the module heuristics are applied to the functional model to
identify a modular product architecture. The embodiment or form definition
phase then attempts to solve each module with one part (or as few as
possible). The critical advantage of the conceptual DFA method is that it
does not require a physical prototype or completed design geometry, thus
reducing the number of design iterations before seeing DFA benefits. One
case study compares the conceptual DFA method with the Boothroyd and
Dewhurst DFA method and shows their equivalence in part count
reduction. A second case study examines the evolution of products over the
years. This study reveals the evolution of products into designs with smaller
part counts, closely matching the modules identified by the conceptual DFA
method. This lends credence to the method proposed in this paper as a
useful tool for reducing the design cycle time