If you're going to design a system that sporadically has many users, you need to build it with enough server support.
Scheduling from home is nice. Being able to access my schedule from almost anywhere is also nice.
Doesn't work when needed. Most of the nurses at the hospital put their schedule in at 7 am on a certain Monday. We aren't even a large hospital and more often than not, the scheduler doesn't work. We get errors like "The requested service is temporarily unavailable. It is either overloaded or under maintenance. Please try later." or "Unable to load user." or "Unable to load (put just about anything here)" or "Waiting for response from server ."