Planning towing processes at airports more efficiently

• This paper introduces a new model for scheduling push-backs at airports.
• The model reflects all relevant operational specification.
• We consider a heterogeneous fleet, time windows, multiple depots and multiple trips.
• We present a column generation heuristic as solution procedure.
• In a case study we evaluate the efficiency of manual schedules and derive managerial insights.

This paper addresses the towing process of airplanes as part of the turnaround process. We introduce a VRP based MIP model which assigns different types of towing tractors to jobs with specified service time windows. The objective function minimizes operating costs subject to operational restrictions such as technical compatibility of tractor types with plane types. Our modeling approach allows for multiple depots as well as multiple trips. To solve the model we develop a column generation heuristic. Computational results show the superior behavior of the proposed heuristic compared to the original MIP formulation solved with CPLEX. In a case study we derive insights which support schedulers in their daily work. For this, we identify cost drivers and evaluate the efficiency of manual schedules in retrospect.