Frequently (and often inappropriately) decision making in the work environment has been analyzed and modeled in terms of isolated decisions made by one person. In reality, decision making is a continuous, interpersonal process usually involving several ``decision makers'' aiming at dynamic and cooperative control of the state of affairs at work. Based on original contributions from researchers and research teams, this book provides an urgently needed cognitive approach to models of distributed decision making, exploring the basis for design of decision support systems in various complex, collective, modern work environments. It identifies the state of the art of modeling distributed decision making and the problems imposed by modern high-tech systems. A also formulates promising research avenues.