3.85 - Airport Capacity Management - Towards a Slot Allocation Modelling Approach Compliant with IATA Rules

Project Description

Given the rapid air traffic growth, demand often exceeds available capacity at the busiest airports worldwide. To cope with this problem, airports may implement demand management mechanisms. Under such mechanisms, airport managers produce adjustments in the schedules of flights requested by airlines to control the number of flights scheduled at peak hours by distributing flights more evenly over the day and/or limiting the total number of flights scheduled in a day. The IATA slot allocation process has been the dominant mechanism practiced by the overwhelming majority of busy airports outside the United States (more than 300 airports worldwide). Under this process, the airports provide a value of “declared capacity”, which determines the number of “slots” available to allocate to the airlines per hour (or any other unit of time). For each season, the airlines submit their slot requests to a slot coordinator that must allocate available slots in the most neutral, transparent and non-discriminatory way. The underlying slot allocation process is very complex, with multiple criteria, rules and priorities, indicated in the Worldwide Slot Guidelines (WSG). Recently, some optimization models have appeared in the literature with the goal of supporting slot coordinators to better accommodate airlines’ preferences at congested airports. However, they do not fully comply with the rules set by IATA as well as with some important constraints faced by the airports, limiting their applicability at slot-controlled airports. Accordingly, the main goal of this PhD thesis is to develop a modelling approach aiming to assist slot coordinators in the decisions they take during the slot allocation process. This approach must be compliant with IATA guidelines and take into account all the airport operational and regulatory constraints in order to be totally efficient when applied to the real world. Afterwards, using the modelling approach developed, we aim to provide some recommendations concerning potential changes in the current IATA slot allocation process.

Research Team


  • Nuno Ribeiro
  • António Pais Antunes
  • João Pita

Carnegie Mellon University

  • Alexandre Jacquillat
Financial Support
  • FCT
Stage of Progress
  • Concluded in 2019