A device detects and diagnoses correlated anomalies of a network. The device includes an anomaly detection module receiving a first data stream including an event-series related to the network. The anomaly detection module executes at least one algorithm to detect a potential anomaly in the event-series. The device further includes a correlating module receiving a second data stream including other event-series related to the network. The correlating module determines whether the potential anomaly is false and determines whether the potential anomaly is a true anomaly.