REPRESENTATION OF DESIGN FUNCTIONS IN EXPERIENCE-BASED DESIGN

In the experience-based approach to design, new design problems are solved by retrieving and adapting the design cases encountered in the past. The adaptation task itself can be solved by instantiating and applying modification plans on the retrieved design. The usefulness of this approach depends on the ability to retrieve a design case similar to the current design task and to select a modification plan that is relevant to the task of adapting the retrieved design. This paper describes a scheme for organizing memory of design cases and modification plans in the domain of physical devices. The design cases in this scheme are indexed by the functions that the stored designs can deliver and the modification plans are indexed by the types of differences between the functions desired of and the functions delivered by a known design. The representation of design functions is grounded in a component-substance model of the functioning of devices. The component-substance model leads to a content theory of design functions which in turn suggests a taxonomy of modification plans. The KRITIK system instantiates this scheme for representing design functions and organizing design cases and modification plans around them.