Class diagram
Library system
Member, Loan, Book and Copy — the model that distinguishes work from item.
- Category
- Education
- Diagram type
- Class diagram
- Elements
- 4
- Connectors
- 3
What it is for
Book and Copy are separate because a library lends a physical copy, not a title. Getting this wrong is the most common modelling mistake in library systems.
More about the class diagram makerWhen it helps
- A teaching example for modelling
- Designing a lending system
- Explaining identity versus instance
