Proceedings of the Annual Meeting of the Cognitive Science Society

Recent research has demonstrated the value of re-using old plans rather than creating plans from scratch. This approach to planning creates the need for efficient and flexible plan adaptation methods to transform a past plan to fit the current problem. A characteristic of plans is that they often fail. This creates the need for efficient and flexible plan repair methods. W e propose a uniform treatment of the two issues, plan adaptation and repair, based on a combination of Case-Base Reasoning and heuristics. Plan adaptation involves incremental modification of the old plan, and fixing of anticipated problems through similarity-based retrieval of cases that supply appropriate modifications. Plan repair involves explanation based retrieval of previous failures that supply possible repairs. A selected repair is then adapted to fit the current failure. The proposed approach gives a planner the flexibility to access a broad range of adaptation and repair strategies not available to planners that use either of the two methods in isolation.The approach has been implemented in the PERSUADER, a case-based planner that generates and repairs plans to resolve labor management disputes.