A method for the study of cascading effects within lifeline networks

The following research is in keeping with the current international and national trend to establish effective facility management plans, based on antagonistic notions of maximal production and minimal risks. The application of this approach to lifeline networks is complex, considering that the failure of these networks can cause extensive consequences for populations and upon socio-economic activities. Effectively, lifeline networks are generally strongly interrelated, which favours the propagation of vulnerabilities from one network to another through cascading effects. A methodology has been developed in order to define, characterise and assess the transfer of vulnerability between lifeline networks. The methodology is based on three specific steps. We first perform an exhaustive assessment of the initial vulnerability and characterise its potential consequences. We then transfer these potential consequences to the other networks through cascading effects. Finally, the transferred consequences are defined as vulnerabilities. Such a methodology, which relies on a complete assessment of consequences, can only be carried out via consequence studies, rather than the usual scenario approaches, in order to evaluate all possible situations. We will present the three main steps of this methodology, which is currently centred on the precise definition of the links that bond the various networks. The consequence studies that we recommend will then be explained, followed by the presentation of a case study of a hydroelectric power generation network and a power transportation network. This example will allow us to validate the preceding concepts.