Use Case Diagram

Easily visualize your system's functionality with use case diagrams

PayPal Credit Payment Identity <<Service>> Service Provider Authentication Online Shopping <<include>> <<include>> View Items Make Purchase Checkout Client Register Registered Customer Customer New Customer Web

What is a Use Case Diagram?

Learn More

Why Make Use Case Diagrams?

Learn More

Use Case Diagram Symbols

Learn More

Use Case Diagram Tutorial

Learn More

Use Case Diagram Tips

Learn More

Use Case Diagram Examples

Learn More

How to Make UML Diagrams

Learn More

UML Diagram Tips

Learn More

Other UML Diagrams

Learn More

With SmartDraw, You Can Create Many Different Types of Diagrams, Charts, and Visuals

Learn More

What is a Use Case Diagram?

A use case diagram is a dynamic or behavior diagram in UML. Use case diagrams model the functionality of a system using actors and use cases. Use cases are a set of actions, services, and functions that the system needs to perform. In this context, a "system" is something being developed or operated, such as a web site. The "actors" are people or entities operating under defined roles within the system.

Back to top
User management subsystem
Airport Use Case Example

Why Make Use Case Diagrams?

Use case diagrams are valuable for visualizing the functional requirements of a system that will translate into design choices and development priorities.

They also help identify any internal or external factors that may influence the system and should be taken into consideration.

They provide a good high level analysis from outside the system. Use case diagrams specify how the system interacts with actors without worrying about the details of how that functionality is implemented.

Back to top

Basic Use Case Diagram Symbols and Notations

System

Draw your system's boundaries using a rectangle that contains use cases. Place actors outside the system's boundaries.

System symbol - use case diagram
Use Case

Draw use cases using ovals. Label the ovals with verbs that represent the system's functions.

Use case symbol - use case diagram
Actors

Actors are the users of a system. When one system is the actor of another system, label the actor system with the actor stereotype.

Actor symbol - use case diagram
Relationships

Illustrate relationships between an actor and a use case with a simple line. For relationships among use cases, use arrows labeled either "uses" or "extends." A "uses" relationship indicates that one use case is needed by another in order to perform a task. An "extends" relationship indicates alternative options under a certain use case.

Relationship symbol - use case diagram
Use Case Template

Use Case Diagram Tool Tutorial

Start with one of SmartDraw's blank UML diagram templates or an included use case diagram example. You can quickly add shapes and users and connect them. To add text, just click and type.

Back to top

Tips for UML Use Case Diagrams

When thinking of use cases, think of the end goal of a user. They don't want to "login" or "sign up." That's not a use case. The use case is more like "make a purchase."

Actors don't have names. They're not "Bob." They represent the role of someone interacting with the system.

Keep your names short and the size of your use cases consistent for a professional look.

For a detailed implementation of a user's goal use a sequence diagram.

Back to top
Simple Use Case Example

Use Case Diagram and Other UML Examples

The best way to understand use case diagrams is to look at some examples of use case diagrams.

Click on any of these UML diagrams included in SmartDraw and edit them:

UML Use Case DiagramUML Use Case Diagram UML State DiagramUML State Diagram UML Class DiagramUML Class Diagram

Browse SmartDraw's entire collection of UML diagram examples and templates

More Use Case Diagram Information

Try SmartDraw's Use Case Diagram Software Free

Discover why SmartDraw is the best use case diagram software today.

By continuing to use the website, you consent to the use of cookies.   Read More