Use Case Diagram – Payment Processor System

A Use Case Diagram visually represents the interactions between actors and the functionalities (use cases) of the system. In the case of a Payment Processor, this helps illustrate how users and systems initiate and handle payment transactions securely and reliably.

Actors Involved:

1. Customer – Initiates and authorizes payments.
2. Merchant – Requests payments, processes refunds.
3. Payment Gateway – Communicates with financial networks.
4. Issuing Bank – Approves or declines payments.
5. Acquiring Bank – Settles funds to the merchant.
6. System Administrator – Manages system operations.
7. Fraud Detection System – Scans for suspicious activities.

Main Use Cases:

• Initiate Payment
• Authorize Payment
• Process Payment
• Verify Fraud Risk
• Confirm Payment
• Refund Payment
• Generate Transaction Report
• View Payment Status
• Manage System Configuration

Explanation of Use Cases:

• Initiate Payment: Customer begins a transaction via merchant interface.
• Authorize Payment: System verifies user identity and card/account validity.
• Verify Fraud Risk: Payment data is scanned for patterns or risk.
• Process Payment: Gateway contacts issuing and acquiring banks.
• Confirm Payment: Final status is returned to merchant and customer.
• Refund Payment: Merchant may reverse a transaction.
• Generate Transaction Report: Admin or merchant creates reports.
• View Payment Status: Status checks can be performed by customer or merchant.
• Manage System Configuration: Admin modifies system settings, fraud rules, etc.