Communication is in this paper seen as the foundation for purposeful human-human activity in dynamic environments. Coordination is a central issue in large systems such as military organisations, enterprises, or rescue organisations, and communication is needed in order to achieve coordination in such systems. This paper suggest a holistic approach to control, where control in a large system is seen as an emergent product of human interaction, focusing on human-human communication from a technical, organisational, temporal, and social perspective. © Springer-Verlag London Limited 2007.