Runway scheduling during winter operations

This paper presents an optimization model for the runway scheduling problem under consideration of winter operations. During periods of snowfall, runways have to be intermittently closed in order to clear them from snow, ice, and slush. To support human planners with the resulting complex scheduling tasks, we propose an integrated optimization model to simultaneously plan snow removal for multiple runways and to assign runways as well as take-off and landing times to aircraft. We formulate the model as a mixed-integer linear problem. To improve the computational tractability of our exact approach, we develop pruning rules and valid inequalities. Additionally, we derive initial start solutions heuristically. We validate and benchmark the model with realistic data from a large international airport and compare the results to a practice-based heuristic approach. We also demonstrate the applicability of our algorithm to large-scale aircraft landing instances from the literature. A computational study shows that our solution approach computes runway schedules which cause significantly less aircraft delay cost within a few seconds.