We have different monitoring containers in our company (SCOM with Veeam Management Pack, Nagios, etc.). All these systems forward their alarms over an event dispatcher platform into our ITSM. In this ITSM, events/alarms are redirected to the appropriate operations team where tickets appear depending on alarms severity. Let me explain one of many examples why this ID is important for us.
If an urgent alarm is generated within Veeam, a priority 1 alarm is generated in ITSM based on this, which means an SMS will be sent to the person in charge (Prio 1 leads to an SMS, while Prio 2 and less will create a ticket). If for any reason, this alarm is gone in Veeam (automatically) some minutes later, an event with Status=Reset/resolved is generated. We forward this (Reset)-alarm to our ITSM as well and the original alarm will be closed and a further SMS will be sent tot he person in charge, that he knows that nothing is to do. This matching of Alarm with Prioritiy 1 and Resolve-Alarm can be done only if I have a unique identifier, otherwise I can't do this match.
This is an elementary feature for us. Actually we use Veeam Management Pack with SCOM and there it is possible, because I have an ID within SCOM. But I want to switch from MP to Veeam ONE because of the better reporting, but I'm able to switch only in the case the alerting works as explained above.
I'm not a native english speaker, but I hope you understand what I mean?