シナリオ
A library system needs to model books, copies, members, librarians, loans, reservations, and fines with clear ownership and multiplicity rules.
この図に含まれるもの
図の背後にある意思決定を読み解く。
01
Separate Book (metadata) from BookItem (physical copy) to allow multiple copies and track status per copy.
02
Use composition for Library-Book and Book-BookItem, aggregation/association for member loans and reservations, and dependency for fine generation.
Use this diagram when designing a library circulation system, integrating with an OPAC, or modeling inventory and loan lifecycle.