A method of modeling dynamic system performance includes enabling a user to create a user-defined static behavior model of a user-defined system of computers, networks and/or bridges. A library of blocks is provided that each represent a computer, a network and/or a bridge for the user to use in defining a user-defined static behavior model, at least some of the blocks in the library of blocks may include one or more block parameters that are user definable. The static behavior model is automatically converted into a dynamic behavior model that is compatible with a simulator and is read into the simulator. A plurality of Monte-Carlo simulations are run on the dynamic behavior model to produce a plurality of simulation outputs, which are analyzed and the analyzed results are outputted.