A Multi-objective Approach to Flight Scheduling and Fleet Assignment in Hub Network

Abstract

The hub-and-spoke (HS) network is a widely used business strategy by airlines to optimize their operations and increase their reach by connecting multiple destinations through a central hub and the majority of the passengers are transit passengers. The airline schedule planning process starts with the flight scheduling problem (FSP) to generate a timetable in advance of six months. Then the fleet assignment problem (FAP) is examined to determine aircraft types. This sequential solution approach causes suboptimal solutions and the schedule must be adjusted to increased demand. Due to the complexity of this problem this study focuses specifically on incremental schedule design with one hub two-flight leg network. This study presents a Multi-Objective Mixed Integer Programming Model for integrated FSP and FAP to adjust the generated timetable with launching new flights. Two solution approaches are proposed to decide the new proposed flight’s time aircraft type and passenger assignment: the Weighted Goal Programming Model (WGPM) and the Lexicographic Goal Programming Model (LGPM). This study shows that there is a conflicting relationship between cost and C0<inf>2</inf> emissions in the flight scheduling process. If carbon dioxide emissions are prioritized airlines need to schedule more flights with small-capacity aircraft. © 2025 Elsevier B.V. All rights reserved.