See, this looks very logical, and a "command based UI" is great.

But the diagram is missing _all_ the complex steps, that makes this type of system a lot of work to build and maintain. You need to be able to cancel. You need to be able to extend bookings, or change the room type. Sometimes, this will incur a fee, and sometimes not.

In my experience (not from hotel systems), the operators _will need_ a way to actually edit the full state of the bookings. A registration form and a read-only 'booking view' will not cut it.

I think it's a good idea to keep the "command-based UI" going for external/end-users though.