What is the type of notification that should be sent when a threshold has been reached, something has changes or a failure has occurred?

An emergency change is a change management record type used when an urgent unplanned fix must bypass normal approval timelines - it is not a notification generated by threshold or failure detection.

An alert is the ITIL-defined notification sent to signal that a threshold has been reached, an unexpected change has occurred, or a failure has been detected within the IT environment. Alerts are generated and acted upon within the Event Management process and typically trigger downstream actions such as automatic incident creation or operator intervention.

'Emergency event' is not a standard ITIL term - ITIL classifies events as informational, warning, or exception types, and the notification mechanism for threshold and failure conditions is specifically called an alert.

A request for change (RFC) is a formal proposal submitted to Change Management to authorize a planned modification to the environment - it is not a system-generated notification triggered by thresholds or failures.