An enterprise threat detection (ETD) pattern is executed against received log event data from one or more computing systems. Using the ETD pattern, an event threshold is determined to have been exceeded. Entities associated with an alert created based on the exceeded threshold are determined and, at runtime, a severity value is calculated for each determined entity associated with the alert. A selection is received of a determined entity on which to perform mitigation action activities. Mitigation action activities associated with the determined entity are written into an activity record data record. A mitigation action activity is closed on the determined entity and a determination performed that all mitigation action activities associated with all entities related to the created alert have been closed. The created alert is closed.