1. An apparatus comprising: a memory to store a data structure representing a multi-echelon network having one or more service parts; and a processor and logic executable thereon to, for each of at least a subset of the one or more service parts, calculate, for the service part, a location within the multi-echelon network, for which allocating the service part to the location provides a greatest gain in system availability per item cost, allocate an additional instance of the service part to the location, recalculate the gain in system availability per item cost based, at least in part, on the additional instance of the service part allocated to the location, and repeat the process of allocating an additional instance of the service part to the location and recalculating the gain in system availability per item cost until an average gain in system availability per item cost decreases.