Level 1 data flow diagram for a real estate management system showing six core subsystems: Authentication, Property Management, Customer Inquiry, Sales and Transactions, Task Operations, and Reporting. Data flows from Business Owners, Agents, and Customers through process nodes into eight normalized data stores including TblUsers, TblProperties, TblInquiry, TblSales, and TblPayment. This architecture demonstrates clear separation of concerns and role-based access control, essential for multi-user platforms handling sensitive property and financial data. Fork this diagram on Diagrams.so to customize subsystems, add data validation rules, or extend it to a Level 2 detailed flow. The design supports audit trails and reporting by maintaining distinct transaction and task tables.