The Operational Layer (OL) directly addresses the ATM system. It aims to provide a thorough analysis of the ATM system as it is today, focusing on the technologies currently available and how a controller utilizes them. Based on these insights, ensuring user (ANSPs and Airlines) alignment, user stories and subsequently the requirements on how AI based decision support can bring benefit to the ATM operations, will be developed. Thereby, the OL will also investigate the operational usage of the probabilistic information from the Predictive Layer and evaluate through the Risk Framework its impact on the ATM operations.