A FUNCTIONAL-APPROACH TO REDESIGN

This paper describes a methodology to assist in the identification of possible conceptual design variants during redesign. The approach is b ased on functional reasoning and involves: (1) the structural and func tional analysis of an existing design; (2) the production of abstract representations of functions and design entities using conceptual grap hs; and (3) design interrogation based on a functional tree approach. The research reported in this paper also focuses on the definition and the representation of elementary mechanical functions. Extended Backu s-Naur Form (EBNF) notations are used to structure in a computable for m, the relevant information (or design knowledge) conceptualised in ei ther the conceptual graphs or the functional trees. EBNF syntax is als o used to formulate rules which aid the partial automation of the reas oning process. The EBNF notations can be mapped to any programming lan guage. A diaphragm valve is used as a case study to demonstrate the ap proach.