This report presents results from the Air Traffic Controllers' (ATCOs') task analysis conducted in five different en-route control centres in Europe. The approach of an Integrated Task Analysis (ITA) was employed, using cognitive interviews, behavioural observations, post-observational interviews and flight progress reconstruction methodology to allow a process description of the en-route controllers' tasks, which focuses on the cognitive aspects. Furthermore, a generic structural breakdown of the job level is provided. The report reviews some of the current results of controllers' job and task analyses and it describes the methods of data collection. The cognitive processes and structures of the controllers' tasks are described at different levels in this report.