Creating a use case diagram can help you capture and communicate the functional requirements of a system from the perspective of the actors, define and clarify the scope and boundaries of a system ...

Use case diagrams are a powerful tool for documenting the functional requirements of a system. They show the actors, the use cases, and the relationships between them in a visual and concise way.

Use Case Diagrams Use case diagrams describe a set of actions (called use cases) that a system should or can perform in collaboration with one or more external users of the system (called actors).