Determine the interface classes and entity classes for the following use case. Give attributes of entity classes.

Use case: Check-out Customer

Summary: A customer checks-out the hotel.

Actors: Desk Clerk, Customer, Bank

Precondition: Customer had checked-in the hotel.

Description:

1. The desk clerk inputs a room number for check-out.

2. The system displays the bill including the total amount for payment.

3. If the customer pays it with a credit card, the customer swipes the card on the card reader. The system requests charging the amount from the bank. If the card payment is successful, the bank returns a reference number and the system prints out the receipt through the receipt printer.

4. The system updates the payment information on the bill.

5. The system prints the bill via the bill printer.

Alternatives:

Step 3: If the customer pays it by debit card, the customer swipes the card on the card reader and enters a PIN, and then the system requests charging the amount from the bank. The bank returns a reference number to the system if the PIN is valid. If the PIN is invalid, the system allows the customer to enter another PIN numbers three times. If payment is successful, the system prints out the receipt through the receipt printer.

Step 3: If the customer pays it by cash, the desk clerk inputs the amount to the system.

Step 3: If customer payment is not successful, the desk clerk asks the customer another payment type.

Postcondition: A customer has checked out.