ABSTRACT
The socio-technical systems on which modern society is based tend to increase in complexity, partly because the technology in itself becomes more powerful and partly because we come to depend more and more on the systems we have created, hence keep tinkering with them to improve their performance. The increasing complexity is not confined to each system by itself but also has the unavoidable consequence that the systems become more closely coupled, i.e., that the interaction and dependency between individual systems increase. It seems as if we are caught in a vicious circle that goes as follows: (1) technological innovations open up new possibilities and enable the construction of new or improved systems; (2) we use the improved systems to make our lives 'easier' - faster planes and trains that travel with shorter intervals, more powerful power plants with narrower operating limits, longer tunnels in difficult environments, communication (sight, sound, data) everywhere and anytime, and so on - and thereby quickly come to depend upon them; (3) in order to meet the demands for safe and reliable operation we require further technological innovation, which - unintentionally - may create new possibilities, etc.
