Entity-Relationship diagram for a comprehensive library management system modeling five core entities: BUKU (books), ANGGOTA (members), PETUGAS (staff), PEMINJAMAN (loans), and KATEGORI (categories). The schema captures book metadata including ISBN, title, author, publisher, and stock levels, while tracking member registrations, staff credentials, and loan transactions with due dates and fine calculations. This normalized design demonstrates best practices for managing library operations—member registrations, book inventory, staff access control, and loan lifecycle tracking with penalty management. Fork this diagram on Diagrams.so to customize entity attributes, add audit tables, or extend relationships for your institutional requirements. The many-to-many relationship between BUKU and KATEGORI via BUKU_KATEGORI junction table supports flexible book classification.