Notice of Retraction.

Conceptual design is a design stage where initial design solutions are developed and the design concepts are generated. The initially developed design concepts should be further refined, so as to ensure its manufacturability, better performance, lower manufacturing cost, and so forth. Various methods and design models have previous been proposed to support conceptual design but very few are specifically for design concept refinement. In this paper, we propose to apply a Critical Path Method (CPM), originally used for project management in the field of operations management, to help refine the design concepts. The definition of behavioural process used for design concept generation is expanded to incorporate information relating to the time durations of individual behaviours, and the expanded behavioural process is used as the network, whereby the critical path is to be identified and exploited. The procedure of applying the CPM for design concept refinement is also presented. A design case of an assembly workstation is studied, where the initial design solution is refined with the proposed methodology to demonstrate its applicability and usefulness. Keywords-conceptual design; design refinement; critical path method