Class Diagram 1b1mz

Assignment 2 Point of Sale Terminal Management System Problem Statement: Construct a design element for Point of sale terminal management system that can be used for buying and selling of goods in the retail shop. When the customer arrives at the post check point with the items to purchase. The cashier records each item, price and adds the item information to the running sales transaction. The description and price of the current item are displayed. On completion of the item entry the cashier informs the sales total and tax to the customer. The customer chooses payment type (cash, cheque, credit or debit).After the payment is made the system generates a receipt and automatically updates the inventory. The cashier handovers the receipt to the customer. UML diagram:

Activity diagram:

Use case specification : *Use Case Name: Check out Actors: Customer and Cashier Preconditions: Customer queue up to reach POS terminal and cashier is available Flow of events: 1. Customer arrives at POS terminal with all items to be purchased 2. Cashier and starts new sale 3. Cashier scans the items to be purchased using bar code scanner 4. System retrieves item specifications from catalogue and records sale line item, and presents description, price, quantity and running total. Cashier repeat until last item is scanned. 5. System calculates total price with taxes and display to customer 6. Cashier asks the mode of payment 7. Customer selects mode and make payment, and system handles the payment. 8. System records completed sale and sends sale information to the external Inventory system for stock update. 9. System presents the receipt. 10. Customer leaves with receipt and all goods purchased. Post Conditions: Payment is approved. Sale is recorded and saved in the system. Receipt is printed and inventory is updated.

*Use Case Name: Payment Actors: Customer and Cashier Preconditions: Cashier scanned all the items and total is available on display screen. Flow of events: 1. Cashier asks for the mode of payment 2. Customer chooses the mode of payment either debit/credit, cash or reward/gift card. 3. Cashier selects the method on POS software. 4. Customer make the payment 5. Payment approved message and receipt is generated. Alternatives: 1. Customer chooses to pay by any combination of three payment methods. 2. If customer chooses to pay by debit/ credit but enters the wrong pin. 3. If customer selects card/debit payment and tap the card but tap is not applicable. 4. If customer chooses to pay by cash but don’t have sufficient amount.

5. If customer chooses to pay by gift or reward card but the balance is not enough. 6. If customer enters the wrong pin three times, the card will be blocked. 7. If the total sale amount is above $100, the tap on card will not work. Post Conditions: Payment is approved..

*Use Case Name: Place Order Actors: Customer ,Cashier Pre-conditions: 1. Give Product Information 2. Update Flow of Events 1. The Use Case starts when the customer selects Place Order. 2. The system displays the Place Order Screen 3. The customer enters their name and address. 4. The customer will enter product codes for products they wish to order 5. For each product code entered 4.1 Use Give Product Information 4.2 The system will add the price of the item to the total. end 6. The customer will enter credit card payment information. 7. The customer will select submit. 8. The system will the information and save the order as pending 9. Use Update 10.The order is marked confirmed, an order id is returned to the customer, and the use case ends. Alternative Flow of Events At any time before selecting submit, the customer can select cancel. The order is not saved and the use case ends Post Conditions: Order is placed. *Use Case Name: Update Product Quantities Actors: Inventory System Flow of Events 1. The Use Case starts when a request to Update Product Quantities is received. 2. If the quantity is positive then 2.1 the system will send a request to the Inventory System to add that amount to the stock on hand for a product. else

2.2 the system will send a request to the Inventory System to subtract that amount from the stock on hand for a product. end if 3. The Inventory System will send an acknowledgment and the Use Case ends. Post Conditions: Inventory is updated

*USE CASE: Process Sale Primary Actor: Cashier Preconditions :Cashier is identified and authenticated Success End Condition Sale is saved. Receipt is printed. Stock data updated. Payment authorization approvals are recorded. Basic Flow: 1 Customer arrives at POS checkout with goods to purchase. 2 Cashier starts a new sale. 3 Cashier enters item identifier. 4 System retrieve item information from the catalog system and, records sale line item and presents item description, price, and running total. Cashier repeats steps 3-4 until indicates done. 5 System calculates and presents total price. 6 Cashier tells Customer the total, and asks for payment. 7 Customer pays and System handles payment. 8 System records completed sale and sends sale information to the external Inventory system for stock update. 9 System presents receipt. 10 Customer leaves with receipt and goods. EXTENSIONS: At any time, System fails: To recovery and correct ing, ensure all transaction sensitive state and events can be recovered from any step of the scenario. 1. Cashier restarts System, logs in, and requests recovery of prior state. 2. System reconstructs prior state. 2a. System detects anomalies preventing recovery: 1. System signals error to the Cashier, records the error, and enters a clean state. 2. Cashier starts a new sale. 3a Invalid identifier: 1. System signals error and rejects entry. 3b There are multiple of same item: 1. Cashier can enter item category identifier and the quantity. 3-6a Customer asks Cashier to remove an item from the purchase:

1. Cashier enters item identifier for removal from sale. 2. System displays updated running total. 3-6b Customer tells Cashier to cancel sale: 1. Cashier cancels sale on System. 3-6c Cashier suspends the sale: 1. System records sale so that it is available for retrieval on any POS terminal. 4a The item’s price is not the customer wanted (e.g., Customer complained that the item is offered at a lower price): 1. Cashier enters override price. 2. System presents new price. 6a Customer says they intended to pay by cash but don’t have enough cash: 1a. Customer uses an alternate payment method. 1b. Customer tells Cashier to cancel sale. Cashier cancels sale on System. 7a Paying by cash: (UC Handle Cash Payment) 7b Paying by credit: (UC Handle Credit Payment) 7c Paying by check: (UC Handle Check Payment) Non-Functional Requirements 1 Touch screen Ul on a large flat monitor. Text must be visible from 1 meter. 2 Credit authorization response within 30 seconds 90% of the time. 3 Somehow, we want robust recovery when access to remote services such the invent tory system is failing. 4 Language internationalization on the text displayed. USE CASE Process Gift Coupon Sale (extends UC Process Sale) EXTENSIONS: 7a Customer presents coupons: 1. Before handling payment, Cashier records each coupon and System reduces price as appropriate. System records the used coupons for ing reasons. 1a. Coupon entered is not for any purchased item: 1. System signals error to Cashier.