1. A method for supplying multiple items through a network of inventory staging areas and distribution points, comprising: determining, using a processor, inventory stocking levels at a staging area and distribution points, and inventory shipments between said staging area and distribution points and between the distribution points, using an optimization formulation whose objective function is to cover maximum overall demand at the distribution points in a given period of time, and to meet the said demand at minimum total cost, the optimization formulation further allowing for re-balancing of inventory between the distribution points through cross-shipping over intervals of time at least based on changing demand at the distribution points over the intervals of time.