Using indicators for system complex safety

In our modern societies, technological systems are taking on a large part in numerous domains such as automatic control, calculation, communication, information technologies, etc. They are put in place in more and more fields e.g. production, defense, national security, space, etc. These very important developments are offering new possibilities such as distributed cooperative and concurrent decision making based on complex dynamic systems or on advanced simulation capacities. To facilitate decision making in various fields such as transport, energy or even risk management, it is necessary to define indicators generated by such systems in order to deliver engineers or managers an image of the considered object and it´s evolution. This image must be coherent, reliable and sustainable in order to participate at the decision in a complex sociotechnical environment. The aim of the article is to present our approach to define this category of new indicators.