Applicability of Current Complexity Metrics in ATM Performance Benchmarking and Potential Benefits of Considering Weather Conditions

Air traffic control is one of the most important stakeholders in the air traffic system and responsible for a safe and efficient air traffic management and traffic flows. Developments in air traffic and changes in the market structure induces the necessity of performance evaluation in air traffic management, done by institutional and academic studies. One of the key influencing factors on air traffic productivity and efficiency is expected to be the air traffic complexity, which contributes to the workload of air traffic controllers and thus limit the airspace capacity. The Performance Review Unit of EUROCONTROL developed a metric to assess the air traffic complexity in order to subject complexity in benchmarking activities. This paper analyses the calculation and the applicability of this complexity score by applying different methods and considering multiple operational levels. It appears that the complexity score contains an unexpectedly high correlation to other metrics (for example, adjusted density), while expected correlations, for example to productivity, weather phenomena or the airspace structure used, do not occur. These significant shortcomings tend to interpret the complexity score as a tendency only.