The standards for network management developed by the open systems interconnection working groups and prescribed by the OSI/NM Forum are based on the managed object and manager-agent concepts. Because multi-level management systems will exist, a management system must be able to support both manager and agent roles simultaneously. This manager role could be to agents, managed by the system and the agent role could be to a superior manager. Such a management system model is proposed and compared with other models defined for network management. Based on the model, an implementation architecture for management systems is described covering both the manager and agent roles. Aspects of a user interface for a network management system are also described. Some unique features of the user interface for multi-vendor, integrated network management are high-lighted.