Most of the stuff I work on are request from other staff members, which has to go through a web application we use. This normally works fine, as the staff can see their "priority" level on the ticket, and I can (normally) change it something more realistic and assign it to myself or another team member. This has been working well for years. It works especially well when people don't communicate between their own departments, and someone calls up to tell us something "isn't working", but in fact it's working under the new change request. It gives us details of who asked for and when, and often why. Great for auditing. 🙂
What really bugs me though is when people phone and ask if we can do something as they need it "urgently", and try to get around the ticketing system. We'll say yes and we can start work shortly based on the conversation, but they need to load the request, and that we can't do the job fully till they do so. An hour (3 days) passes by, and no request has come, so we halted work at the preliminary stage. They then phone to chase it and wonder where it is. Of course, they then get upset when the new time scale is 2 days from when they load it. Most of these people learn after the 2nd mistake, but we still have a few that kick and scream when the only person they have to blame is themselves for not opening a ticket.
Excuse my typos and sometimes awful grammar. My fingers work faster than my brain does.