1. A method for estimating a duration of simulating a process embodied in a directed graph comprising: loading a directed graph for traversal in a simulation engine including a hardware processor; exploding all branched paths for all branched nodes emerging from merge point nodes of the directed graph; identifying a plurality of nodes in the directed graph; determining a probability of simulation for each node in each exploded branched path; estimating a duration of simulation by the simulation engine for individual ones of the nodes in the exploded branched path; proportioning the estimated duration of simulation for each of the nodes in the exploded branched path by a corresponding probability of simulation; summing the estimated duration of simulation for the individual ones of the nodes presenting the produced estimate; identifying a plurality of loops of the nodes in the directed graph; estimating a number of iterations for each of the loops by computing Nx for node x in a loop and for each loop according to the equation Nx=[R/(1−Px)]−R, where R is a number of repetitions for traversing the directed graph and where Px is a probability that a traversal of the directed graph includes node x in a given repetition, and adding the computed Nx to an existing running total value for Nx in node x; and, summing the duration of simulation for each of the number of iterations associated with the individual ones of the nodes to produce the estimate of the duration of traversal of the directed graph.