Business Overview

What Business Problem Does This System Solve?

CardDemo is a credit card account management system for financial institutions. It automates the complete lifecycle of credit card operations including:

• Customer account management and credit limit control
• Credit card issuance and status management
• Transaction processing and authorization with fraud detection
• Bill payment processing and balance management
• Monthly statement generation for regulatory compliance
• User administration and role-based security

Why developers need to know this: Understanding the business domain helps you make better technical decisions. When you modify transaction processing code, you need to know that credit limits must be enforced (business rule) and that overlimit transactions must be rejected with proper error codes.

Who Are the End Users?

1. Customer Service Representatives (Regular Users)

Customer-facing staff who:

• View and update account information during customer calls
• Process transactions and bill payments
• Review transaction history for dispute resolution
• Generate reports for customer inquiries

2. System Administrators (Admin Users)

Back-office personnel who:

• Manage user accounts and security
• Configure transaction types and categories
• Maintain system reference data
• Oversee system operations

3. Automated Batch Processes

Scheduled system jobs that:

• Post daily transactions from external sources (nightly)
• Generate monthly account statements
• Perform data imports/exports for integration
• Calculate interest and process fees

Why developers need to know this: Different user types have different security requirements. When implementing new features, consider whether the function should be available to regular users, admins only, or both. Screen layouts and workflows should match how customer service reps actually use the system during live calls.

Key Business Capabilities

1. Real-Time Account Management

   • View complete account profiles including balances, credit limits, and transaction history
   • Update customer information and account settings instantly
   • Enforce credit limits and account status rules in real-time

2. Credit Card Lifecycle Management

   • Issue new cards linked to customer accounts
   • Manage card status (active, suspended, closed) for fraud prevention
   • Handle card expiration and renewal processes
   • Support multiple cards per account

3. Transaction Processing and Authorization

   • Process credit and debit transactions with full validation
   • Real-time authorization with credit limit checking
   • Fraud detection and transaction marking
   • Maintain complete audit trail with timestamps

4. Payment Processing and Account Balancing

   • Process bill payments immediately reducing account balances
   • Generate payment transaction records for audit
   • Support full balance payment workflow
   • Update account balances in real-time

5. Automated Statement Generation and Reporting

   • Generate monthly statements in text and HTML formats
   • Include complete transaction detail and account summary
   • Support transaction reports by date range and account
   • Meet regulatory compliance requirements for periodic statements

Why developers need to know this: These capabilities drive the system architecture. Transaction processing requires immediate consistency (VSAM), authorization needs high throughput (MQ), and statements need bulk processing (batch). When adding features, ensure they align with these core capabilities and don't break existing business workflows.

High-Level Business Process Map

Process Flow Explanation:

Online Operations:

• Users authenticate and are routed to appropriate menu based on role
• Customer service reps handle account, card, transaction, and payment operations
• Admins manage system users and configuration
• All operations update master files immediately for real-time consistency

Batch Operations:

• Nightly batch posts transactions from external sources (POS, ATM, online)
• Validates each transaction against card/account files
• Updates account balances and transaction history
• Monthly batch generates statements for all accounts

Why developers need to know this: This map shows the system's major workflows and data dependencies. When debugging issues, trace through this flow to understand where data comes from and where it goes. When adding features, identify which part of the flow is affected and ensure proper integration with existing processes.

Developer Takeaways

1. Domain Knowledge is Critical: Credit card processing has strict business rules (credit limits, authorization codes, fraud detection) that must be enforced in code. Don't bypass validation logic.

2. Data Integrity Matters: Account balances, credit limits, and transaction records must always be consistent. Understand transaction boundaries and file locking.

3. Real-Time vs. Batch: Know which operations run online (immediate user feedback) vs. batch (high volume processing). Different performance and error handling requirements.

4. Security by Design: User authentication and role-based authorization are fundamental. Never expose admin functions to regular users.

5. Audit Trail Requirements: Every transaction must be timestamped and traceable. Don't delete transaction records, mark them as voided instead.