Use Case Diagram in UML

The purpose of a use case diagram in uml is to demonstrate the different ways that a user might interact with a system. In UML, use cases are diagrammed to be easily understood, no matter who is looking at the diagram.

With Lucidchart's extensive UML shape library, it's easy to make use case diagrams of all types. Try it today!

Try it now
Sign up free

Use Case Diagram Example

use case diagram in uml

Consider the example above. A man with a chain saw interacts with the environment around him. Depending on the situation and the context of the situation, he might fall into one of many different use cases. Does he seem to be on his way to work? Is there anything ominous about the way he is wielding his chainsaw? For example, if he is using the chainsaw in a non-occupational setting, we might have reason to think that he falls within the scope of "scary".

Use Case Diagram Notation

The notation for a use diagram is pretty straightforward and doesn't involve as many types of symbols as other UML diagrams. Here are all the shapes you will be able to find in Lucidchart:

  • Use cases - Use cases are the horizontally shaped ovals. This represents the different uses that a user might need.
  • Actors - represented by stick figure people and are the people actually employing the use cases
  • Associations - represented by a line between actors and use cases. In a more complex diagram, it is important to know which actors are associated with which use cases. In the example above, the lines are simply drawn for the sake of consistency.
  • System boundary boxes - a box that sets a system scope to use cases. All use cases outside the box would be considered outside the scope of that system. For example, Psycho Killer is outside the scope of occupations in the example above.
  • Packages - A UML shape that allows you to put different elements into groups. Just as with component diagrams, these groupings are represented as file folders.

Use Case Diagram for ATM

atm use case diagram example

Here is a popular use case diagram. It lays out the varying ways that people might interact with an ATM.

Use Case Diagrams in Visio

Any use case that you want to use in Visio will be compatible with Lucidchart if you have a Pro or a Team account. You can import a use case diagram from Visio into Lucidchart in either .vdx or .vsd formats. If you need to send a use case diagram to someone with Visio, you can export any UML diagram you create (or any file for that matter) to a .vdx format.

UML Use Case Diagram Tutorial

We are putting together video tutorials on how to make the above use case diagrams with Lucidchart.

Use Case Diagram Template

Lucidchart is a great use case diagram tool for those who don't want to be tied to just one machine. It allows you to work on the go and backup your files online.

Start your Lucidchart trial here. No download or plugins required.