Integrating Planning and Temporal Reasoning for Domains with Durations and Time Windows

The treatment of exogenous events in planning is practically important in many domains. In this paper we focus on planning with exogenous events that happen at known times, and affect the plan actions by imposing that the execution of certain plan actions must be during some time windows. When actions have durations, handling such constraints adds an extra difficulty to planning, which we address by integrating temporal reasoning into planning. We propose a new approach to planning in domains with durations and time windows, combining graph-based planning and disjunctive constraint-based temporal reasoning. Our techniques are implemented in a planner that took part in the 4th International Planning Competition showing very good performance in many benchmark problems.