For complex systems, there may be many system boundaries that represent smaller, more specific modules. The system boundary is a visual limitation of the entire system module. Inclusions: Inclusion links represent additional functions necessary to complete a system and may form connections between two use cases or use cases and actors. These links may connect actors to use cases or multiple related use cases without depending on one another for functionality. Generalizations: Generalization links represent relationships between actors that depend on each other's functions to complete their role within a system.Įxtensions: Extension links represent optional functions within a system. Actors may connect to use cases and other people through a variety of communication links representing different relationships such as:Īssociations: Association links represent interactions between actors and use cases. Communication linksĪ solid, straight line can represent an actor's interaction with a use case or use cases' interactions. This function may be automatic or manual and may link to an actor or function independently. Use cases, often represented by an oval or circle encompassing text, describe a system function that is an actor or person can start or use.

This may include users, customers, clients or employees Actors may interact with the system internally or externally. They interact with each step of the process. Related: Systems Thinking What is involved in a use case diagram?Ī case use diagram includes a few key components: ActorsĪctors are individuals who have a relationship within the system. A use case diagram shows a model scenario in which individuals interact with a system using a series of specialized symbols and connectors. They may show systems in computer software, businesses or customer experiences. These diagrams show a very broad view of a system. Related: Q & A What Is a Flowchart? What is a use case diagram?Ī use case diagram is a visual summarization of interactions and relationships within a system. In this article, we define use case diagrams, discuss their key elements and purpose and offer examples of use case diagrams in a variety of settings. Use case diagrams can help professionals visualize systems in many fields, including sales, software development, business and manufacturing. A use case diagram is a tool that maps interactions between users and systems to show the interactions between them. During the design and development stage, organizations can use visual representation to show their existing systems.

Use case diagrams online