Synthesis and evaluation of preliminary designs

Abstract: "Design is a process of producing a description of a system or process to satisfy a set of requirements. To support the designer in the identification and composition of components of design solutions requires both synthesis and evaluation methods. Such methods can provide a systematic approach to design, allowing the designer to pursue more alternatives and to evaluate the alternatives based on a discourse of criteria and value. The use of knowledge based techniques for the exploration of synthesis and evaluation methods maintains a separation of method and knowledge, allowing the designer to guide the methods with qualitative or empirical knowledge without sacrificing the benefit of a systematic approach.In this paper, models of knowledge based synthesis and evaluation are presented. Synthesis is based on a constraint directed search through a design space that is decomposed into subsystems, components, and constraints. Evaluation is based on the concept of Pareto optimality for identifying a set of optimal solutions. Both synthesis and evaluation are integrated in a single model for producing alternative design descriptions for a given set of requirements. This model has been implemented as an environment for developing knowledge based synthesis programs, where the experienced designer defines a knowledge base and the designer uses the resulting knowledge base to produce design solutions.