Heuristics for Constraint-Directed Scheduling with Inventory

Despite the importance of the management of inventory in industrial scheduling applications, there has been little research that has addressed reasoning about inventory directly as part of a scheduling problem. In this paper, we represent inventory, inventory storage constraints, and inventory production and consumption in a constraint-directed scheduling framework. Inventory scheduling is then used to investigate heuristic commitment techniques based on the understanding and the exploitation of problem structure. A technique for the estimation of probability of breakage for resource and inventory constraints is presented together with a heuristic commitment technique based on the estimate of constraint criticality. It is empirically demonstrated that a heuristic commitment technique that exploits dynamic constraint criticality achieves superior overall performance.