In this study, the authors propose the formalisation of the Simultaneous Slot Allocation Problem (SSAP), that extends, in two directions, the current way of allocating airport slots in Europe. The SSAP requires, first, to perform the slot allocation at all airports simultaneously and, second, to respect airspace sector capacities. The authors solve the SSAP with two algorithms based on metaheuristics, namely Iterated Local Search and Variable Neighborhood Search, and with an algorithm based on an integer linear programming model. They compare these algorithms on randomly generated instances and show that for small instances metaheuristics are competitive with the integer linear programming model. Nevertheless, the integer linear programming model is unable to solve medium or large instances because of memory and computation time requirements. Metaheuristics, instead, can deal with large instances, allocating slots to more than 99.8% of flights.
