A resource based framework for planning and replanning

Abstract

The aim of this paper is to combine standard planning and replanning methods 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.

Previous plans can be used both for creating new plans and for modifying plans. Since we are often interested in reusing only a part of these previous plans, we extend the Action Resource Formalism with incomplete plans. To efficiently represent such incomplete plans we use the notion of a gap. We maintain a library of incomplete plans (with gaps), and we present operators to insert plan parts from this plan library into the current plan. We prove this set of plan operators to be complete.

Generalizing the refinement planning approach, we present a template algorithm for both planning and replanning using the ARF and its plan library and plan operators. Finally, we show that existing (re)planning methods and heuristics nicely fit into this framework.