Unifying Planning and Replanning in the ARF

The aim of this paper is to combine standard planning, replanning and multi-agent planning into a rigorous unifying framework, extending an existing logic-based approach to resource-based planning. In this Action Resource Framework (ARF), actions and resources are the primitive concepts. Actions consume and produce resources. Plans are structured objects composed of actions and resource schemes and an explicit dependency function specifying their interrelationships. Plans can be changed by applying plan operators to them. We consider both planning and replanning as plan transformation processes and we introduce some operators for plan transformation. We prove some sets of plan operators to be complete. The explicit representation of the plans and their inputs and outputs (resources) turns out to be particular useful in modeling multi-agent (re)planning as processes of exchanging services and resources among agents. Finally, we show that existing (re)planning methods and heuristics fit into this framework.