Scheduling ground-handling services: a bi-objective approach

Preparing an aircraft for its next flight requires a set of interrelated services involving different types of vehicles. Planning decisions concerning each resource affect the scheduling of the other activities and the performance of the other resources. Considering the different operations and vehicles instead of scheduling each resource in isolation allows integrating decisions and contributing to the optimisation of the overall ground-handling process. This goal is defined through two objectives: (i) minimising the waiting time before an operation starts and the total reduction of corresponding time windows, and (ii) minimising the total completion time of turnarounds. We combine different technologies and techniques to solve the problem efficiently. A new method to address this bi-objective optimisation problem is also proposed. The approach has been tested using real data from a major Spanish airport, obtaining different solutions that represent a trade-off between both objectives. Experimental results permit inferring interesting criteria on how to optimise each resource, considering the effect on other operations. This outcome leads to more robust global solutions and to savings in resources utilization.