A system is provided to monitor network performances. The system maintains a database of performance abnormalities, alarms and events from a system of monitored elements. The system automatically identifies a possible cause of a specific alarm by correlating the specific alarm with a plurality of events using the database. The system displays the cause of the specific alarm. The database includes alarms and events of network devices, network systems, and network applications. The specific alarm consists of a notification of an occurrence of the plurality of events.