Time Table Edge Finding with Energy Variables

Moli Yang, Andreas Schutt, Peter J. Stuckey

Abstract: Cumulative resource constraints can model scarce resources in scheduling problems or a dimension in packing and cutting problems. In order to efficiently solve such problems with a constraint programming solver, it is important to have strong and fast propagators for cumulative resource constraints. In this paper, we develop a time-table edge-finding energy propagator for cumulative constraint which can reason more strongly based on energy. We give results using this propagator in a lazy clause generation system on rectangle packing and evacuation scheduling problems. We are able to prune the search space and reduce solve time compared with a time-table or time-table edge-finding propagator.