ABSTRACT
Introduction Our society is relying on a set of complex socio-technical systems called critical infrastructures (CI). Although the exact definition of what constitutes a CI varies such systems as electrical power distribution systems, telecommunication systems and railroad systems are generally considered to be CIs. The current trend is that those systems, which used to be isolated from each other, are becoming more and more interconnected and dependent on each others’ services. In fact, today one can often describe them as a “system of systems” (Little, 2003) and it can sometimes be difficult to know where one system ends and another one begins. This creates some difficult problems from a crisis management perspective. Perhaps most notably is the fact that these systems have become more vulnerable to disruptions across system borders (Amin, 2002) and that the consequences due to perturbations in the services of the systems have the potential to be considerable, both in terms of geographic extent and in terms of number of affected people. The potential for large consequences has been illustrated by, for example, the failure of the communication satellite Galaxy 4 (Rinaldi, Peerenboom & Kelly, 2001; Little, 2002) and the disruption of the power supply to Auckland (Newlove, Stern & Svedin, 2003).
