1. A system for simulating at least one flow parameter of a network, said system comprising: a memory storage device; and one or more processing units coupled to the memory storage device and configured to perform a method comprising steps of: generating a graph representing a network to be simulated; generating an annotated graph from said graph by assigning a weight to edges of said graph based on available data, wherein said weight is selected from a likelihood weight representing a likelihood that a corresponding edge is connected during operation of said network, an impact weight measuring a degree of impact to at least one flow parameter of said network upon disconnection of said corresponding edge, and a combination of said likelihood weight and said impact weight; generating minimal cut sets from said annotated graph; selecting a collection of minimal cut sets that is less than an entirety of said generated minimal cut sets; generating almost isolating scenarios from said minimal cut sets in said collection by removing at least one cut from each of said minimal cut sets; and running a simulation on said at least one flow parameter for said almost isolating scenarios.