Process Models for Design Synthesis

niques in developing design programs provides formalisms for representing p r o b l e m s o l v i n g processes. In this article, the use of AI techniques in modeling design processes is elaborated with the presentation of three models that formalize the representation of design knowledge within a design program. For the purpose of establishing the relevance of the models presented here, a structured approach to the overall process of design is adopted in which the design process comprises three phases: formulation, synthesis, and evaluation. Design formulation involves identifying the requirements and specifications of the design problem. The result of design formulation is sometimes referred to as the design brief or program or, more simply, the definition of the design problem. Design synthesis includes Studies in design methodology provide various structured approaches to the design process. Many books provide definitions and elaborations of the design process: In the structural engineering field, such books include Holgate (1986) and Lin and Stotesbury (1981). More generally, various design methods and techniques are described in Alexander (1964) and Jones (1970). These design methods share the characteristic of prescribing a general set of tasks to be performed by the designer. One problem with design methodologies is that such approaches prescribe what a designer should do but not how. Human designers tend to not use such methodologies because they stifle creativity through a prescription of structured activities. There is a need to identify models of design processes that facilitate design rather than prescribe a design process. There is a need to identify models of design processes that facilitate design rather than prescribe a design process. Articles