Time-Optimal Planning in Temporal Problems

This paper presents TPSYS, a Temporal Planning SYStem, which arises as an attempt to combine the ideas of Graphplan andTGP to solve temporal planning problems more efficiently. TPSYS is based on a three-stage process. The first stage, a preprocessing stage, facilitates the management of constraints on duration of actions. The second stage expands a temporal graph and obtains the set of temporal levels at which propositions and actions appear. The third stage, the plan extraction, obtains the plan of minimal duration by finding a proper flow of actions.