Analogical design and invention is a central task in human cognition. Often during the process the designer/inventor gets stuck; backs off from the problem; and only later, after having put the problem aside, discovers that some famihar plan can be used in a novel way to solve the problem. W e describe a system which uses a causal case memory to check the side effects, preconditions, etc. of incoming events in order to model this phenomenon. The method used makes this work relevant to case-based reasoning as well as design. It also forms a companion issue to execution-time planning.
