The constant increase in airline passenger volume results in either expansion of an airport or more effective use of its existing structures. Major expansions of inner city airports are expensive or physically impossible; thus optimization of existing workflows is an effective option. The improvement of apron workflows, such as turnaround processes, has the biggest potential for more effective use of existing resources. This paper presents the global optimization of interdependent turnaround processes. The stakeholders who are responsible for the turnaround processes, especially the ground handling tasks, have resources such as vehicles. It is essential to optimize their task planning to increase effectiveness. This concept should be adaptable to other logistical areas; but the first prototype was created for airports. While the turnaround contains different processes, the focus here will be on the ground handling processes. These are, for example, the transit of passengers on the apron, the dispatching of luggage, airplane catering, and refueling. These ground handling workflows contain local optimizers. We use a prototypically interface between the global optimizer and its local optimizers (turnaround processes). The global optimizer use local databases for the scheduling of the local optimizers.