Recovering rationale for design changes: a knowledge-based approach

As a compromise between the text-string solution and the automated design solution for capturing rationale for design decisions, it is assumed that the goal of the designer is to satisfy a set of requirements and that the rationale for design decisions can be inferred by comparing how different design alternatives meet these requirements. Accordingly, the rationale for a design change is either to satisfy constraints that were previously violated, or to create a design version that better satisfies the constraints. To implement this approach, mechanisms to evaluate how the device being designed satisfies the requirements at different stages of the design process are proposed. Alternative design solutions are organized into design records, indexed by the design requirements, that can be compared. To organize these design records, a hypertext system is integrated with a knowledge-based framework capable of supporting structural and behavioral models of an engineered device as well as formal requirement representations. The expected benefits of the method and the difficulties associated with it are discussed