Combining Specialized Reasoners and General Purpose Planners: A Case Study

Many real-world planning problems involve substantial amounts of domain-specific reasoning that is either awkward or inefficient to encode in a general purpose planner. Previous approaches for planning in such domains have either been largely domain specific or have employed shallow models of the domain-specific considerations. In this paper we investigate a hybrid planning model that utilizes a set of specialists to complement both the overall expressiveness and the reasoning power of a traditional hierarchical planner. Such a model retains the flexibility and generality of classical planning framework while allowing deeper and more efficient domain-specific reasoning through specialists. We describe a preliminary implementation of a planning architecture based on this model in a manufacturing planning domain, and use it to explore issues regarding the effect of the specialists on the planning, and the interactions and interfaces between them and the planner.