This paper concerns control of stochastic networks using state-dependent safety-stocks. Three examples are considered: a pair of tandem queues; a simple routing model; and the Dai-Wang re-entrant line. In each case, a single policy is proposed that is independent of network load ρ • . The following conclusions are obtained for the controlled network in each case, where the finite constant K 0 is independent of load: The policy is fluid-scale asymptotically optimal, and approximately

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... optimal. The steady-state cost η satisfies the bound where η * is the optimal steady-state cost. These results are based on the construction of an approximate solution to the averagecost dynamic programming equations using a perturbation of the value function for an associated fluid model. Moreover, a new technique is introduced to obtain fluid-scale asymptotic optimality for general networks modeled in discrete time. The proposed policy is myopic with respect to a perturbation of the value function for the fluid model.