That's the thing, there are no systems. It's always a singular system. The issue comes down to the human factor and the process (or lack thereof) that the hotel has in place to inform the housekeeper of new information. They are only as good as what their sheet says in terms of who is checking out and when. If the desk does not input/pass that information on and/or if the housekeeping manager/supervisor/inspector doesn't inform the housekeeper, you're going to get the experience you mentioned. Once the housekeeper gets their board assignment sheet when they come in, that's what are taught to blindly follow unless told otherwise.