Vending Machine Application

List of features

1. Configure machine: Enter in a product and a price for each slot, e.g. chips, $1.00 in Slot 1, candy bar, $2.00 in slot 2, pop $1.50 in slot 3, etc...
2. Track inventory: Keep track of the number of items in each slot, e.g. 3 bags of chips in slot 1, etc...
3. Purchase item: Allow a user to purchase an item using coins (not bills) and return proper change.
4. Validate purchase: Do not allow an item to be purchased if it is unavailable or if the machine does not have enough change
5. Notifcation: If change reserves or inventory fall below pre-defined threshold, or if machine gets jammed, send message to maintenance crew
6. Sales reports: The machine will keep track of sales and has the capability to send back a report on request.
7. Additional Feature Request: Make denominations configurable to handle any arbitrary set of coins without having to recompile the source code.
8. Additional Feature Rquest: Attempt to level change given to prevent a denomination from being exhausted prematurely
9. Additional Feature Request: The machine will present advertising while an item is being delivered
10. Additional Feature Request: The machine will support additional methods of payment, such as credit card or debit.
11. Additional Feature Request: The machine will ask the buyer if he wants additional products, e.g. "Would you like a Pepsi with your Mars bar?"

Example Use-Case/Story: Purchase Item

1. The buyer puts money into the machine. The machine adds up the amount with each insertion and and displays it to the buyer.
2. The buyer enters in the code for the item he/she wishes to purchase
3. The machine validates the code; if the code is invalid, the machine displays an error message; if the amount is insufficient, the machine displays an error message.
4. The machine dispenses the item.
5. If the user presses 'done', the machine returns change; otherwise the user can enter in a code to purchase another item.

Technology