This paper provides a systematic analysisof the relativeutility of basingEBG based plan reuse techniques in partial ordering vs. total ordering planning frameworks. We separate the potential advantages into those related to storage compaction, and those related to the ability to exploit stored plans. We observe that the storage compactions provided by partially ordered partially instantiated plans can, to a large extent, be exploited regardless of the underlyingplanner. We arguethat it is in the ability to exploit storedplans during planning that partial orderingplanners have some distinct advantages. In particular, to be able to flexibly reuse and extend the retrieved plans, a planner needs the ability to arbitrarily and efficiently ‘‘splice in’’ new steps and sub-plans into the retrieved plan. This is where partial ordering planners, with their least-commitmentstrategy, andflexible plan representations,score significantly over state-based planners as well as planners that se...