COGNITIVE MODEL OF MEMORY FOR MECHANICAL-DESIGN PROBLEMS

Mechanical-design activities can be categorized into two classes: creating new designs for new problems, and modifying old designs to fit new problems. The vast majority of mechanical-design activities can be associated with the latter class. In most cases, it is more effective to modify the design process that creates a mechanical artifact than it is to modify the mechanical artifact itself. A scheme for design automation that uses analogical problem solving as its intelligent agent offers an effective method for solving both classes of mechanical design. It is particularly suited to the latter class of design activities. It relies heavily on a knowledge base for storing design cases generated while solving design problems, and retrieving design cases that are applicable in a new design-problem context. In the paper, a cognitive model of memory for storing design plans is presented. The memory model is four layers deep: product design plans, assembly design plans, component design plans, and recurring-engineering-problem design plans. The storage and retrieval mechanism is based on some of the more popular work found in case-based reasoning. To alleviate the situation in which the user(s) operate(s) in a restricted vocabulary set, a semantic network is integrated into the memory model for use as an elaboration and crossreference mechanism. Mechanical-design plans for products, assemblies, mechanical components and recurring engineering problems can be stored and retrieved from the memory model using information found in the description of the design problem. Sample examples are presented to demonstrate the potential of the memory model.