When you are small, with less than 20 people, but you support more than 50 systems, not every person can be an expert on all systems. There are some medical systems that can take a long time to become an expert on the back end processes. We try to have a person who is an assigned back up, but realistically, that doesn't happen. I'm still the expert on the system.

I'm not officially "on call" 24 x 7, because I can mark myself as completely unavailable for short periods of time, but it is understood that I'm available otherwise. People who aren't, don't last long, because you can't tell someone on the operating table that you can't finish their surgery because the IT person won't answer a call, or tell the person who's on the table getting their radiation treatment that we're just going to guess on how much radiation they're getting because the IT person is not available to bring the system back up.

Yes, you can call the vendor, but the IT person can usually get the system back up and running in a few minutes, where a vendor might not even call back for 2 hours or more.