Control of Refitting during Plan Reuse

In plan reuse, refitting is the process of modifying an existing plan to make it applicable to a new problem situation. An efficient refitting strategy needs to be conservative, i.e., it should minimally modify the ex­ isting plan to fit it to the new problem situation. In this paper we present techniques for conservative refitting control by utilizing the annotated dependency structures of an existing plan. The dependency struc­ tures arc used to select the refitting choices that minimize disturbance to the applicable parts of the ex­ isting plan. This localizes the refitting process and minimizes the cost of refitting. We describe how these techniques are incorporated into PRIAR, a frame­ work for flexible plan reuse.