Use Case Definition: A use case describes in narrative prose usually structured the sequence of events actions, transactions, ... of an actor human role, external computer systems, … using a system buying, ordering, managing information to complete a process

Use Case: Example Example: “Borrow Library Resources” Patron arrives with the resources (books, videos, etc.) to borrow and submits them to the Librarian along with his/her library card The librarian records the identification information on the card and the system validates the card [Exception: card not valid, overdue books, etc.] For each resource, the Librarian records the call number. Patron is told about the due dates Patron leaves with the resources Exceptions: Card not valid: Patron is asked to get a valid card and resources are put back on the shelves Overdue Books: Patron is asked to pay the dues in full (Collect Fines use case) before the Borrow transaction can proceed. For more sample use cases and how to document a use case: see http://www.acs.ilstu.edu/faculty/bllim/oo/usecase.htm