The scenario
A university needs a class model for its library system covering borrowing, reservations, fines, and catalog search. The diagram models the core entities and their relationships.
What is in this drawing
Read the decisions behind it.
01
Model user roles with an abstract Account base class specialized by Member and Librarian.
02
Use composition to show that a Book consists of multiple BookItem physical copies.
03
Represent Searchable as an interface realized by Catalog for library search operations.
04
Associate Loan with Member, Librarian, BookItem, and Fine to capture the lending workflow.
Use this diagram when designing a library information system or any domain with physical items, borrowing workflows, and user role hierarchies.
More like this