Use Case UC1: Process Sale
Primary Actor: Cashier
Stakeholders and Interests:
Cashier: Wants accurate, fast entry, and no payment errors, …
Salesperson: Wants sales commissions updated
Customer: Wants purchase and fast service with minimal effort. …
Company: Wants to accurately record transaction and satisfy customer interests. …
Government tax Agency: …
Payment Authorization Service: …
Preconditions: Cashier is identified and authenticated
Success Guarantee (Postconditions): Sale is saved. Tax is calculated. Accounting and inventory is updated. Commissions recorded. Receipt is generated. Payment authorization approvals are recorded.
Payment Authorization Service: …
Main Success Scenario (Basic Flow)
Customer arrives at POS checkout with goods and/or service to purchase
Cashier starts a new sale
Cashier enters item identifier
…
Alternative Flows (Extensions):
a. At any time system fails:
…
3a. Invalid identifier:
System signals error and rejects entry
3b. …
Special Requirements:
Touch screen UI on a large flat panel monitor
Credit card authorization within 30 seconds 90% of time
…
Technology and Data Variations List:
3a. Item identifier entered by a barcode laser scanner
3b. Item identifier maybe any UPC, EAN, JAN, SKU coding scheme
…
Frequency of Occurrence:
Could nearly be continuous
Open Issues:
What are the tax law variations?
Must a cashier take their cash drawer when they log out?