The Air Transport in general and the Air Traffic Management system are formed by a high number of elements, human, organisational and technological, that interact with each other creating a unique system of intrinsic complexity. The variability of the initial conditions and the high number of potential scenarios makes the system performance particularly difficult to predict. As a consequence, the propagation of perturbations and disruption, and the understanding of the allocation of resources needed to mitigate those undesired phenomena, represent a major challenge in today system design.

Technological and procedural solutions are being investigated in a number of research projects, but the adaptability of the system to perturbations has proven a demanding research topic that Europe needs to address to understand the how to build a future operational concept resistant to these undesired events.

There is no definition of resilience in air transport yet and therefore there are no unique metrics for it. Potentially, different metrics take into account different aspects of the resilience of the system. Therefore it is important to develop metrics quantifying the level of resilience of the system and the likelihood of an (undesired) emergent phenomenon to propagate throughout the system without an exact understanding of the different mechanisms to mitigate it.