Design concept as a model for modelling design process and its knowledge

The strategy of decomposing a design problem into subproblems is commonly used in engineering design. One difficulty in applying this strategy to computer-based design systems is the assembly of subproblem solutions to construct a whole solution. Despite its advantages, this design strategy suffers two major problems. First, as constraints are ill defined and implicitly exist among design objects, it is very difficult to articulate and represent design constraints in computable forms. Second, as design subproblems are designated separately in computer-based design systems, the inherent relationships among subproblems are not considered in contriving these subproblems. As a result, recomposing subproblem solutions is hard to do. This paper presents a model for modelling design processes and the knowledge involved. The model is called ‘design concept’, which represents empirical interconnections of design attributes and intraconnections of design subproblems. Topological relations are represented using decomposition trees. The advantages and disadvantages of integratively using decomposition trees and design concepts in facilitating conceptual design are discussed