Human communication, mutual awareness and system dependability. Lessons learnt from air-traffic control field studies

The dependability of many complex and critical systems strongly relies on human operators, both through human reliability and human ability to handle adequately the unexpected events. This paper focuses on ergonomics field studies of air traffic control activities, and more specifically on the analyses of communication within teams of controllers. We show how operators use spontaneously the natural redundancy and diversity of human communication (multimodality, addressing features,…), so as to successfully maintain mutual awareness. This is the key for reliable cooperation, for the sake of global system dependability that rests on mechanisms such as error detection, recovery, and prevention (by anticipation and regulation). This study helps in providing specifications for the design of systems efficiently supporting both human cooperation and human ability to contribute to dependability.