Object-Oriented Software Development with UML - UNU-IIST ...

138 Iterative Development Process1. This use case begins when a Customer arrives ata POST checkout with items to purchase.2. The Cashier records the identifier from each item. 3. Determines the item price and adds theitem information to the running salestransaction.If there is more than one of the same item, theCashier can enter the quantity as well.The description and price of the currentitem are presented.4. On completion of the item entry, the Cashier indicates5 Calculates and presents the sale total.to the POST that item entry is completed.6. The Cashier tells the Customer the total7. The Customer chooses payment method:(a) If cash payment, initiate Pay by Cash.(b) If credit payment, initiate Pay by Credit.(c) If check payment, initiate Pay by Check.10. The Cashier gives the printed receipt to the Customer.11. The Customer leaves with the items purchased.Alternative Courses8. Logs the completed sale.9. Prints a receipt.Line 2: Invalid identifier entered. Indicate error.¾Line 7: Customer could not pay. Cancel sales transaction.¾Use case:Actors:Overview:Pay by CashCustomer (initiator), Cashier.A Customer pays for a sale by cash at a point-of-sale terminal.Typical Course of EventsActor ActionSystem Response1. This use case begins when a Customer chooses topay by cash, after being informed of the sale total2. The Customer gives a cash payment–the “cashtendered”–possibly greater than the sale total.3. The Cashier records the cash tendered. 4. Shows the balance due back to the customer.5. The Cashier deposits the cash received and extractsthe balance owing.The Cashier gives the balance owing to the CustomerReport No. 259, July 2002UNU/IIST, P.O. Box 3058, Macau