Accelerated Event Notification (AEN) is a pop-up notification which notifies operators of a particular/critical events happened in a monitored environment. The Accelerated Event Notification (AEN) system provides a means of accelerating high-priority events to help ensure that systems can continue to run without interruption.
Below is the Reference link on how about AEN and how to configure AEN.
https://www.ibm.com/support/knowledgecenter/SSSHTQ_8.1.0/com.ibm.netcool_OMNIbus.doc_8.1.0/omnibus/wip/uaaen/concept/omn_aen_monitoringfasttrackevnts.html