Increasing airport capacity utilisation through optimum slot scheduling: review of current developments and identification of future needs

TLDR

Busiest airports worldwide suffer serious congestion and delays, prompting urgent capacity and demand management actions, and slot scheduling has emerged as a promising, resource‑sustainable solution for short‑ to medium‑run capacity utilisation improvements. The paper seeks to critically review existing research on declared capacity modelling and strategic slot scheduling. It extends this review by identifying research gaps and proposing concrete directions for modelling and solving advanced single‑airport and network‑level slot scheduling problems. The authors recommend next‑generation slot scheduling models incorporate alternative delay objectives, fairness, equity, resource utilisation, environmental factors, airlines’ utility and acceptability measures, and develop computationally viable, robust, hybrid approaches that capture dynamic, weather‑induced uncertainty at both airport and network levels.

Abstract

Most of the busiest airports worldwide experience serious congestion and delay problems which call for some immediate capacity and demand management action. Solutions aiming to manage congestion through better slot scheduling have lately received a great deal of consideration due to their potential for delivering quick and substantial capacity utilisation improvements. A slot scheduling approach brings promises to cope better with congestion problems in the short to medium run and in a more sustainable way based on existing resources. This paper aims to provide a critical review of current research in declared capacity modelling and strategic slot scheduling. Furthermore, it goes beyond the critical review of current research developments by identifying future research issues and gaps and developing concrete directions towards modelling and solving advanced single airport and network-based slot scheduling problems. Our research findings suggest that the next generation of slot scheduling models should explore variations of currently used objectives (e.g., alternative expressions of schedule delay) and most importantly enrich them with fairness and equity, resource utilisation and environmental considerations. Future modelling efforts should also aim to further investigate airlines' utility of alternative slot allocation outcomes, including various acceptability measures and levels of tolerance against schedule displacements. Last but not least, future research should intensively focus on the development and validation of computationally viable and robust slot scheduling models being able to capture the complexity, dynamic nature and weather-induced uncertainty of airport operations, along with hybrid solution approaches being able to deal with the size and complexity of slot allocation at network level.