This paper proposes a hierarchical control algorithm for an efficient network management of a loosely-coupled system which consists of functional division and duplicating structure with a LAN to enhance reliability and availability. The algorithm is modeled using the Perti-net and verified with the reachability tree. Here, the proposed algorithm is compared with the purely centralized control algorithm and distributed control algorithm in terms of message traffic for the network management. The result shows that the message traffic related to system performance is as low as centralized control algorithm and the system availability is independent of a specific processor failure.