E-commerce support system ERD in Chen notation models a complete order-to-support workflow with users, products, orders, licenses, and multi-level support ticketing. Data flows from users creating orders containing product items, each generating a license, while support tickets track customer issues linked to orders with threaded messages and file attachments. This schema demonstrates normalized relational design for SaaS product distribution, balancing transactional integrity with support case management. Fork and customize this diagram on Diagrams.so to adapt it for your platform's specific product catalog, payment gateway, or support escalation rules. The Chen notation explicitly shows cardinality constraints, making it ideal for communicating database requirements to DBAs and backend teams.