The effects of resupply flexibility on the design of service parts supply systems

We apply simulation optimization to determine the optimal design and stock distribution for a single item supply system with a one-for-one replenishment policy. We investigate both the effect of the number of echelons and the degree of resupply flexibility, considering single-echelon and two-echelon systems with either no resupply flexibility, lateral transhipments only or both lateral transhipments and emergency deliveries. We show that the implementation of an emergency delivery option allows an augmentation of the fraction of customers served by lateral transhipments and that increased resupply flexibility enables increasingly important cost savings.