The order fulfillment process involves more than just filling orders.  It includes all activities necessary to define customer requirements and to design a network and a process that permits a firm to meet customer requests while minimizing the total delivered cost as well as filling customer orders.  This is not just the logistics function, but instead needs to be implemented cross-functionally and with the coordination of key suppliers and customers.  The objective is to develop a seamless process from the supplier to the organization and then on to its various customer segments.

cf. Douglas M. Lambert and Terrance L. Pohlen, "Supply Chain Metrics," The International Journal of Logistics Management, Vol. 12, No. 1, (2001), pp. 1-19.