How do I tell which IT outage is actually critical?

Taking tickets as they come leaves you guessing which outage actually matters, and you often find out the hard way, when the critical one has already sat too long. That is a stressful spot, but it is a sorting problem, not a sign you cannot judge severity. You just need a way to weigh them before you dig in. Critical is not about who filed first, it is about how much stops and for whom. Ask what is actually down, how many people or systems depend on it, and whether there is any way to keep working without it. An outage that halts a whole department, or something customers touch, or a system others are chained to, outranks a single blocked task even if that task was reported earlier. Impact and reach are your measure, not the timestamp. Before diving into the next ticket, pause and ask: what breaks if this waits an hour, and how many are caught in it? Handle the widest, most blocking outage first. That one habit, judging by what is stopped rather than what came in, turns guessing into a call you can defend and stand behind.