Chen ER diagram modeling a comprehensive study planner system with USER, SUBJECT, EXAM_EVENT, SCHEDULE, STUDY_SESSION, FOCUS_LOG, TOPIC, ANALYTICS_REPORT, PRODUCTIVITY_ANALYTICS, NOTIFICATION, REVISION_LOG, and AI_MODEL_FEEDBACK entities. Data flows from users registering subjects and exam events, organizing study schedules with individual sessions tracked via focus logs and revision logs, while analytics entities aggregate productivity metrics and AI feedback. This architecture demonstrates best practices for educational technology platforms: capturing granular study behavior, enabling personalized learning through AI recommendations, and providing actionable productivity insights. Fork this diagram on Diagrams.so to customize entity relationships, add new attributes, or adapt it for your learning management system. The design supports multi-tenant scalability with user-centric data organization and temporal tracking across all study activities.