An Approach to Temporal Planning and Scheduling in Domains with
  Predictable Exogenous Events
  The treatment of exogenous events in planning is practically important in
many real-world domains where the preconditions of certain plan actions are
affected by such events. In this paper we focus on planning in temporal domains
with exogenous events that happen at known times, imposing the constraint that
certain actions in the plan must be executed during some predefined time
windows. When actions have durations, handling such temporal constraints adds
an extra difficulty to planning. We propose an approach to planning in these
domains which integrates constraint-based temporal reasoning into a graph-based
planning framework using local search. Our techniques are implemented in a
planner that took part in the 4th International Planning Competition (IPC-4). A
statistical analysis of the results of IPC-4 demonstrates the effectiveness of
our approach in terms of both CPU-time and plan quality. Additional experiments
show the good performance of the temporal reasoning techniques integrated into
our planner.
