How to Draw a Use Case Diagram in UML
Making a use case diagram doesn't have to be complicated. Once you understand the conventions of UML, you can create and refine UML charts. Follow these steps to draw your own use case diagram in UML.
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SELECT A MEDIUM
The first step to creating a use case diagram is to select a drawing medium. While it can be a good idea to sketch out your ideas on paper first, this method is messy and not scalable. We recommend choosing a software program with dedicated UML components.
This guide will walk you through the steps of drawing a use diagram specifically in Lucidchart. It's a great choice for these types of diagrams because it has an easy-to-learn canvas and pre-drawn symbols for actors, use cases, and systems. Lucidchart also offers several options for customization and real-time collaboration with colleagues.
IDENTIFY THE COMPONENTS
Use case diagrams differ from other UML diagrams by focusing on actors and their interaction with a system. Keep this in mind as you draw your diagram; the structure of a use case diagram should always be organized according to the actor's perspective. Create these diagrams to help your business:
- Define where in a workflow end users interact with a system
- Consider which use cases are inside or outside the scope of your system
- Set out goals that actors achieve
Now that you know when to draw a use case diagram, let's focus on how to proceed. In Lucidchart, create a new document and select Templates > Standard > UML > Basic Use Case Diagram.
ADD SHAPES AND SYMBOLS
Begin by dragging a system boundary box onto your canvas. In Lucidchart, this is labeled a Rectangle Container. For developers, systems represent what you are developing, such as a software component or a complete suite.
Next, focus on your actor. Your use case diagram should reflect the actor's perspective, so ask yourself what the end user wants from the system. Actors are represented by stick figures. Since actors are often people, the symbol is fitting. Rename your actors to reflect their role.
Now it's time to drag use cases onto your system. These ovals represent the activities that actors will perform with the help of your system. For example, if you're developing a check-in mobile application, the system would be the app and the actor would be the user. Possible use cases would be check-in, searching for a nearby venue, and finding friends.
Start with major activities or transactions; leave sub-activities for later. Place each use case in the system that supports it and draw use cases not supported by your system outside the box. For instance, if your check-in app does not support taking photos, but it's on the agenda for a future release, put it outside the system. Drag lines from the actors to the use cases by pulling out a line from a stick figure. This is what organizes your diagram.
Now you should have a simple use case diagram. There are several ways you can customize your chart: add a color scheme, change the font, or add notes. This guide gives you more ideas of how Lucidchart use case diagrams appear when completed.
REVIEW THE FLOW
When creating any diagram type in UML, it's useful to take a step back and make sure the flow makes sense. Have a coworker take a look at your diagram and find any inconsistencies that might have slipped past you.
Try Lucidchart for a modern, innovative solution for drawing use case diagrams in Unified Modeling Language (UML). With in-editor collaboration and sharing, it's a useful tool for beginners and experts alike.