This document is part of an on-going process that will lead to the development of an infrastructure risk analysis for Great Britain. As part of the ITRC study of the “long term dynamics of interdependent infrastructure systems” this study deals the risk of failure of infrastructures in the present and future. This Work Stream 2 (WS2) analysis, out of five work streams, aims to build and apply analytical concepts, theoretical and simulation models and data tools to develop an integrated risk analysis framework. The current document is a compilation of an initial method statement for the infrastructure risk analysis problem. The primary objectives satisfied in this report are:

1. Development of important definitions that will be used throughout the WS2 analysis.
2. Presentation of a mathematical formalisation of the risk analysis framework that deals
   with quantifying probabilistic hazards, infrastructure failure probabilities, damage
   evaluation, and economic loss estimation.
3. Building a framework that establishes a unified methodology for reliability analysis,
   damage assessment, loss estimation, and risk analysis.
4. Outline key issues and steps required for implementation of the risk analysis methodology.