1. A method of assessing failures in a network, comprising: receiving, via a user interface at a failure analysis system, a plurality of user-specified potential failure conditions that have not yet occurred within the network, simulating each of the plurality of failure conditions on a model of the network, evaluating, by the failure analysis system, performance of the network under each of the plurality of failure conditions, the performance being defined by a plurality of performance measures, mapping, by the failure analysis system, each performance measure of each failure condition to one of a plurality of degrees of degradation severity, rank ordering the plurality of failure conditions by the failure analysis system, based on the degree of degradation severity of each performance measure for each failure condition, wherein the rank ordering includes mapping the degree of degradation severity of each performance measure to an ordered set, and providing, by the failure analysis system, a failure assessment report based on the rank ordering of the plurality of failure conditions.