Scheduling algorithms for ATM applications — Tools and toys

Planning, particularly scheduling of limited resources is one of the main tasks of ATM. More than 10 papers of ATM seminar 2009 covered scheduling. None of these papers, however, generalizes its results so that they are suitable for different ATM scheduling problems. In this paper we extend common heuristics. We show that the A * algorithm should be preferred to Branch&Bound(B&B). A* achieves the same quality results, but with a runtime reduction of 50 to 70 %. The presented Take-Select heuristic with or without iterations in combination with a base algorithm like A* or B&B enables the optimization of some hundreds of elements. It enables the needed trade-off between objective function quality and runtime performance by adjusting the window size. We demonstrate the performance of Greedy, Tabu-Search, Branch&Bound, A* and Take-Select with different window sizes by applying them for ground vehicle and aircraft scheduling. We use our algorithms to optimize the landing sequence at an airport with very closely spaced parallel runways and show that these algorithms are also able to simultaneously optimize the usage of multiple resources.