This paper describes current research toward automating the redesign process. In redesign, a working design is altered to meet new problem specifications. This process is complicated by interactions between different parts of the design, and many researchers have addressed these issues. An overview is given of a large design tool under development, the Circuit Designer's Apprentice. This tool integrates various techniques for reengineering existing circuits so that they meet new circuit requirements. The primary focus of the paper is one particular technique being used to reengineer circuits when they cannot be transformed to meet the new problem requirements. In these cases, a design plan is automatically generated for the circuit, and then replayed to solve all or part of the new problem. This technique is based upon the derivational analogy approach to design reuse. Derivational Analogy is a machine learning algorithm in which a design plan is saved at the time of design so that it can be replayed on a new design problem. Because design plans were not saved for the circuits available to the Circuit Designer's Apprentice, an algorithm was developed that automatically reconstructs a design plan for any circuit. This algorithm, Reconstructive Derivational Analogy, is described in detail, including a quantitative analysis of the implementation of this algorithm.

No abstract

Derivational Analogy is a technique used to adapt a previous design plan to solve a new problem. However, derivational analogy requires that this design plan be saved at the rime of design. Design plans are generally not available unless design occurred with an automated design assistant. which could capture the details of the design process. Some design assistants do not have this ability, and many designs exist which were developed without an automated assistant. A method is proposed for recreating a design plan for a design, using design rationale information. Rationales are used to choose from possible design decisions, and to bias the design plan towards the new problem. This method enables the use of a design in derivational analogy even when the design plan is not available and demonstrates a significant potential for rationales in automated design. This paper discusses in detail the knowledge required and techniques applied for automated reconstruction of derivational histories.

No abstract