Rack: have some sort of live rack of rooms, so it includes state, stocked items and it is crucial for it to be very easy to change, so add a component to change state easily.
invoices: let the user make invoices, each invoice must be printable and contain room number, invoice ID, date, and a list of items sold.
inventory/products: the user must be able to see how many products are left and how many are missing,inventory is at a basic level a sum of all products with the same name.
products need to be on a by hotel basis so for each hotel there's a different list of products in stock
prices on items should be editable
invoices can be "reported" or "in house" chosen by the user at creation
"close register" functionality
printing invoices
fetch specific invoices by room, ID or date
always an "invoice approval" with all the invoices made
mostly finished...