Evaluating Plans through Restrictiveness and Resource Strength

The planning and scheduling framework which is the object of this paper consists in a loosely-coupled integration which is achieved by cascading a classical planner and a general purpose scheduler. The output of the planning phase yields a partially ordered plan which is then integrated with time and resource constraints to produce a scheduling problem. The research described in this paper is aimed at understanding the structural trademarks of the causal knowledge that a scheduling tool can inherit from STRIPS-based reasoners. Specifically, we analyze quality of the plans in terms of two wellknown properties of scheduling problems, namely the Restrictiveness and the Resource Strength. To this end, we describe a set of experiments carried out on a series of state-ofthe-art planners aimed at assessing the bias of different planning strategies in the context of the loosely-coupled framework.