Overall safety performance of the air traffic management system: the italian ANSP's experience on APF

Air Traffic Management (ATM) system needs to be continuously monitored to evaluate safety performance of operational activities, in order to maintain and improve safety levels. However, standard metrics of counting events (incidents, accident and near misses) are not able to give usable information to decision makers in supporting their strategies. As safety events are generally rare, traditional statistical analysis generally fails to represent the overall system performance. This paper discusses the development of the Aerospace Performance Factor (APF) methodology in a real case implementation. The research presents to ATM safety managers and researchers the main framework and the roadmap to develop a specific system-wide assessment, giving them guidelines based on lessons learned. Starting from international regulations and describing the European APF context, this paper offers a detailed description of the APF implementation to the Italian Air Navigation Service Provider ENAV s.p.a., one of the first ANSPs to adopt, customize and implement the methodology.