Use case diagrams in Software Engineering - Mini Project: Build & Apply

Creating a Simple Use Case Diagram

📖 Scenario: You are designing a use case diagram for a library management system. This system allows users to borrow and return books, and librarians to manage the book inventory.

🎯 Goal: Build a basic use case diagram structure that shows the main actors and their interactions with the system.

📋 What You'll Learn

Define the main actors involved in the system

List the key use cases for each actor

Show the relationships between actors and use cases

Include the system boundary to enclose the use cases

💡 Why This Matters

🌍 Real World

Use case diagrams help teams understand system requirements and user interactions clearly before building software.

💼 Career

Software engineers, business analysts, and project managers use use case diagrams to communicate system functions and plan development.

1

Define the Actors

Create a list called actors containing the exact strings 'User' and 'Librarian' representing the main actors in the system.

Software Engineering

# Create the list of actors
# Your code here

Need a hint?

Actors are the people or roles that interact with the system. Here, we have two: User and Librarian.

2

List the Use Cases

Create a dictionary called use_cases with keys 'User' and 'Librarian'. Assign to 'User' the list ['Borrow Book', 'Return Book'] and to 'Librarian' the list ['Manage Inventory'].

Software Engineering

actors = ['User', 'Librarian']
# Create the use_cases dictionary
# Your code here

Need a hint?

Use cases describe what actions each actor can perform in the system.

3

Define Relationships

Create a list called relationships containing tuples that link each actor to their use cases exactly as follows: ('User', 'Borrow Book'), ('User', 'Return Book'), and ('Librarian', 'Manage Inventory').

Software Engineering

actors = ['User', 'Librarian']
use_cases = {'User': ['Borrow Book', 'Return Book'], 'Librarian': ['Manage Inventory']}
# Create the relationships list
# Your code here

Need a hint?

Relationships show which actor is connected to which use case.

4

Add System Boundary

Create a string variable called system_boundary and set it to the exact value 'Library Management System' to represent the system boundary enclosing the use cases.

Software Engineering

actors = ['User', 'Librarian']
use_cases = {'User': ['Borrow Book', 'Return Book'], 'Librarian': ['Manage Inventory']}
relationships = [('User', 'Borrow Book'), ('User', 'Return Book'), ('Librarian', 'Manage Inventory')]
# Define the system boundary
# Your code here

Need a hint?

The system boundary is a label that shows what system the use cases belong to.