Abstract: A spare capacity planning tool for planning spare capacity in a transport network during a multiple-span failure following a single failure event. The spare capacity planning tool simulates restoration of a transport network regardless of the sequence of failures. The system and method utilize a permutation reducer to minimize the number of sequences to be verified during simulated or actual restoration activities. The permutation reducer reduces the number of sequences to to during simulated restoration activities to a first order function rather than a factorial function of the number of failed spans.