UML use case diagrams: Everything you need to know

Learn how to make Use Case Diagrams in this tutorial. Both beginners and intermediate UML diagrammers will find all the necessary training and examples on systems, actors, use cases, and include and extend relationships. UML Use Case Diagrams show a system or application; then they show the people, organizations, or other systems that interact with it; and finally, they show a basic flow of what the system or application does. This tutorial explains the four main characteristics of Use Case Diagrams: systems, actors, use cases, and relationships. A system is whatever you’re developing. It could be a website, a software component, a business process, an app, or any number of other things. You represent a system with a rectangle. The next aspect of Use Case Diagrams are actors. An actor is going to be someone or something that uses our system to achieve a goal, and they're represented by a stick figure. Use Cases are elements that really start to describe what the system does. They're depicted with an oval shape and they represent an action that accomplishes some sort of task within the system. The final element in Use Case Diagrams are relationships, which show how actors and use cases interact with each other. There are different types of relationships (like association, include, extend, and generalization) that are represented by varying types of lines and arrows. —— Timestamps 0:00 Introduction to use case diagrams 0:44 High level overview and benefits 1:35 Systems: Defining boundaries and scope 2:10 Actors: Who uses the system 3:09 Primary and secondary actor roles 3:57 Use cases: Describing system actions 5:10 Relationships and associations 6:30 Expanding the diagram with more cases 7:35 Include relationships: Required actions 8:24 Extend relationships: Optional behaviors 9:23 Sneezing example for relationships 10:16 Generalization and inheritance 11:06 Use cases with extension points 12:06 Conclusion —— Learn more at: training.lucid.co Sign up at: https://www.lucidchart.com #Lucidchart #UML #UseCaseDiagram #VisualCollaboration #SystemsDesign #softwareengineering About Lucid Lucid Software is the leader in visual collaboration and work acceleration, helping teams turn ideas into reality. Its Visual Collaboration Suite (Lucidchart and Lucidspark) and airfocus, an AI-powered product management platform, help organizations streamline work, foster alignment, and drive business transformation. The most used work acceleration platform by the Fortune 500, Lucid is trusted by 100M+ users worldwide. 🔔 Subscribe for more tips and tutorials:    / @lucid_software   Connect with us Facebook:   / lucidsoftware   Twitter: https://x.com/lucidsoftware Instagram:   / lucidsoftware   LinkedIn:   / lucidsoftware