Use Case Diagram for Library Management System

A use case diagram in UML helps to show the various ways in which a user could interact with a system. For a Library Management System, the use case diagram helps visualize the interactions between users (actors) and the system’s functionalities (use cases). This diagram provides a clear, simplified way to understand how the system operates and what it offers to its users.

Use Case Diagram, referred to as a Behavior model or diagram. It simply describes and displays the relationship or interaction between the users or customers and providers of the application service or the system. It describes different actions that a system performs in collaboration to achieve something with one or more users of the system. A use-case diagram is used a lot nowadays to manage the system.

Use Case Diagram consists of the following components:

1. Actor: Actors are external entities that interact with the system. These can include users, other systems, or hardware devices. In the context of a Use Case Diagram, actors initiate use cases and receive the outcomes. 
2. Use Case: Use cases are like scenes in the play. They represent specific things your system can do.
3. System Boundary: The system boundary is a visual representation of the scope or limits of the system you are modeling. It defines what is inside the system and what is outside. 

Let’s visually map out the relationships and interactions. Below is the textual description of what the diagram would look like:

1. Actors:
   • User (Staff or Student)
   • Librarian
2. Use Cases:
   • Register New User
   • Issue Library Card
   • Request New Book
   • Reserve Book
   • Renew Book
   • Pay Fine
   • Fill Feedback Form
   • Manage Records
   • Delete Records
   • Update Database
3. System Boundary:
   • The system boundary will encompass all the use cases mentioned above.

Below is the use case diagram of a Library Management System

Explanation of Use Case Diagram of a Library Management System

Here, we will understand the designing use case diagram for the library management system. Some scenarios of the system are as follows :

1. User who registers himself as a new user initially is regarded as staff or student for the library system.
   • For the user to get registered as a new user, registration forms are available that is needed to be fulfilled by the user.
   • After registration, a library card is issued to the user by the librarian. On the library card, an ID is assigned to cardholder or user.
2. After getting the library card, a new book is requested by the user as per there requirement.
3. After, requesting, the desired book or the requested book is reserved by the user that means no other user can request for that book.
4. Now, the user can renew a book that means the user can get a new due date for the desired book if the user has renewed them.
5. If the user somehow forgets to return the book before the due date, then the user pays fine. Or if the user forgets to renew the book till the due date, then the book will be overdue and the user pays fine.
6. User can fill the feedback form available if they want to.
7. Librarian has a key role in this system. Librarian adds the records in the library database about each student or user every time issuing the book or returning the book, or paying fine.
8. Librarian also deletes the record of a particular student if the student leaves the college or passed out from the college. If the book no longer exists in the library, then the record of the particular book is also deleted.
9. Updating database is the important role of Librarian.