Maximizing Flexibility: A Retraction Heuristic for Oversubscribed Scheduling Problems

In this paper we consider the solution of scheduling problems that are inherently over-subscribed. In such problems, there are always more tasks to execute within a given time frame than available resource capacity will allow, and hence decisions must be made about which tasks should be included in the schedule and which should be excluded. We adopt a controlled, iterative repair search approach, and focus on improving the results of an initialpriority-drivensolutiongeneration procedure. Central to our approach is a new retraction heuristic, termed max-flexibility, which is responsible for identifying which tasks to (temporarily) retract from the schedule for reassignment in an effort to incorporate additional tasks into the schedule. The max-flexibility heuristic chooses those tasks that have maximum flexibility for assignment withintheir feasible windows. We empirically evaluate the performance of max-flexibility using problem data and the basic scheduling procedure from a fiel...

• Type: Conference
• Year: 2003
• Where: IJCAI
• Authors: Laurence A. Kramer, Stephen F. Smith
• Keywords: IJCAI 2003, IJCAI 2007, Incorporate Additional Tasks, Max-flexibility Heuristic Chooses, Retraction Heuristics