About Use Case Diagram Generator

Generate UML use case diagrams with actors, use cases, and relationships. Part of the DevTools Surf developer suite. Browse more tools in the Diagrams & Workflows collection.

Use Cases

• Capture functional requirements for a new system at a scope level useful for both business and technical stakeholders.
• Identify all system actors and their relationships to use cases before beginning detailed design.
• Communicate system boundaries and scope to project stakeholders in a non-technical format.
• Derive test cases from use case scenarios to ensure requirements coverage.

Tips

• Keep actors to system-boundary roles (external user types, systems), not individual people or internal implementation components.
• Use include relationships for mandatory steps that are part of another use case (authentication is always included by any protected action).
• Use extend for optional steps that can conditionally extend a use case — not every path needs a separate main use case.

Fun Facts

• Use case diagrams were formalized by Ivar Jacobson in his 1992 book 'Object-Oriented Software Engineering: A Use Case Driven Approach.' Jacobson is one of the three authors of UML (with Booch and Rumbaugh).
• Use cases as a requirements technique predate the diagram form — Jacobson first described the use case concept in a 1987 Ericsson internal technical report while designing the AXE telephone switching system.
• A 2010 survey found that use case diagrams are the most commonly used UML diagram in requirements analysis phases of software projects, despite criticism that the diagram adds little information beyond a use case table.

FAQ

When should I use a use case diagram vs. a user story?

Use case diagrams show scope and actor relationships visually — useful at project inception. User stories describe individual behaviors with acceptance criteria — useful for sprint planning. They complement rather than replace each other.

What's the include vs. extend relationship?

Include: always performed as part of the base use case (login always includes authenticate). Extend: conditionally adds behavior to a base case without modifying it (checkout may extend with apply coupon). Extend is commonly misused for mandatory behavior — use include instead.