A computer program that is embodied on a storage medium for execution on a processor is provided. With this computer program, A current cost is calculated for each transition on a bus having a predetermined width for a functional circuit so as to form a transition cost matrix. Then, a predetermined number of the lowest cost transitions for from the transition cost matrix is determined so as to generate a probability transition matrix. The product of the probability transition matrix and the transition cost matrix can be iteratively determined, while also updating the probability transition matrix until the probability transition matrix converges.