Workload Balancing in Periodic Aircraft Maintenance Checks: A Lexicographic Heuristic Approach Under Zone Constraints

Abstract

This study aims to provide solution approach to the task allocation problem for periodic aircraft maintenance checks with a flexible and parametric model, which is capable of adapting to various set of constraints. The primary goal is to minimize the fluctuations in workload (man-hour) along the planning period regarding maintenance packages in order to ensure the efficient use of resources and manage aircraft ground times. The problem is formulated as a packing problem while incorporating spatial conflict rules and periodicity requirements. The contribution of the proposed solution approach relies on its dynamic input structure, which can incorporate task lists and constraints without being dependent on a specific aircraft type or maintenance program. A lexicographic optimization structure is adopted to sequentially minimize workload imbalance, maximize interval utilization for tasks with high labor requirements, and minimize active zone diversity within maintenance checks. The proposed algorithm iteratively improves the solution using local search method after the greedy assignments. Computational experiments conducted on both narrow-body and wide-body fleet scenarios show that the proposed method achieves a substantially smoother workload profile across maintenance checks while successfully managing defined spatial conflicts. Although a controlled reduction in task interval utilization is observed, this trade-off is shown to be operationally acceptable when equalized workload demand are prioritized. The methodology proposed in this study can serve as a Decision Support System for airline operators and maintenance organizations, thanks to its speed and capability in generating feasible solutions.