Best of luck replacing Epic. I used to work on a healthcare cost accounting system, and epic data was just one source we ingesting into our platform. MASSIVE amounts of data, everything that happens in a hospital is tracked and coded. In the US, hospitals are notorious for (among other things) being extremely slow to upgrade systems for day-to-day operations.
Once my wife was in for a routing procedure, and as the nurse was entering info into the computer by her bed, she paused, then raised her hand. Someone came over with clipboard and then called someone else on a radio. In a couple of minutes a 'runner' came over, and showed her how to do what she needed to do in the system.
"But I always do that over in this other screen"
"Well, it's not there anymore. Did you do the training?"
I asked the nurse what was going on, and she said they had upgraded their Epic system several days ago, and "everything changed".
The problem was that they use it day in and day out, so any kinds of changes massively alters their workflow. To the point that to keep operating, they had to have many runners with radios for about a week (to cover all shifts) to help people get used to the changes after a release upgrade.