1. Example  Software for a virtual library (borrowing books using the Internet) Internet terminal DB

2. Task  Define main requirements  Create Use Case diagram capturing the requirements  Create an architecture design  Create conceptual design  Create sequence diagrams  Create class diagram

3. Actors  Two main actors:  The person borrowing books, User  The person administering the library, Librarian

4. The User  A user should be able to:  Search for books  Reserve book  Login to be able to borrow books

5. Search for books Name: Search for books Initiator: User Goal: Get a list of books 1. User enters search criteria, e.g. author, title, ISBN, etc. 2. The system searches its database for matches 3. The system returns the result Extensions: 2. Search failed, no results a.System allows User to try again b.Resume at 1

6. Reserve book Name: Reserve book Initiator: User Goal: Reserve specified book 1. The User wants to reserve specified book 2. The system marks specified book as reserved Extensions 2. All copies of the book are already reserved a.The system adds the User to reserve queue b.The system notifies the User c.Stop

7. The Librarian  The Librarian should be able to:  Mark a book as available when a book is returned (Unreserve book)  Add new book to the database

8. Unreserve book Name: Unreserve book Initiator: Librarian Goal: Mark a book as available 1. The Librarian gets a returned book 2. The Librarian unreserves the book Extensions 2. Another user has reserved a copy of this book a. The system marks the book as reserved by the next user in the reserve queue b.Stop

9. Use Case diagram

10. Three-Tiers Client-Server Architecture Database driver Library server Admin client User client Presentation layer (Client) Application layer (Server) Data layer

11. Library server conceptual design

12. Sequence diagram for Search

13. Sequence diagram for Unreserve

14. Sequence diagram for login, search and reserve

15. Library server class diagram