3 Cost-Effectiveness Analysis of Measures to Reduce Vulnerabilities in

"Protection of Society "(BAS) is a joint project between the Directorate for Civil Defence and Emergency Planning (DSB) and the Norwegian Defence Research Establishment (FFI). The purpose of the project is to design and evaluate cost-effective civil emergency measures. An overall methodology for cost-benefit analysiskost-effectiveness analysis of civil emergency measures was presented at 14 ISMOR (1). This methodology has now been further developed and applied in an analysis of measures to reduce vulnerabilities in the public telecommunication system. Modem telecommunication systems are vulnerable when multiple simultaneous incidents occur. If severe failures in the telecommunication system occur, the loss of telecommunication services will have a serious impact on all critical functions in modem society. Several measures have been identified to reduce these vulnerabilities and the negative consequences they entail for the society. The effectiveness of the measures with regard to the Total Defence's ' ability to operate has been calculated by using a multicriteria decision model, which combines the technical telecommunication system with the societal system of the Total Defence. The cost of each measure has also been estimated using a probabilistic cost model. The paper briefly describes the nature of complex socio-technical problem that has been analysed and the results of the analysis. The main focus will then be on the applied methodology.