A domain independent algorithm for adapting temporal plans

Plan adaptation is useful in faster generation of plans. We propose a domain independent algorithm for adapting plans with durative actions. Given a plan which is to be adapted to the new problem, our algorithm retains a portion of the old plan (set of actions) that can be useful in solving the new problem. The actions in the portion of the old plan are adjusted to the new durations. These actions are applied one after another according to their start times, starting from the initial state of the new problem. The state with the lowest heuristic value among the intermediate states obtained after application of each action is selected. A plan is found out from this state to the goal state of the problem and added to the set of actions applied to arrive at this state. The resulting set of actions forms the plan for the new problem. Experimental results show that adapting a temporal plan using our algorithm can be very efficient.