Summary: Several business actors having some needs and goals as related to the restaurant and business use cases expressing expectations of … Once you’ve hammered out the kinks in your goals, use Lucidchart to diagram the interactions between the use cases and actors to write the success story for your project. Use Case Diagram with Example . Use case diagrams model the functionality of a system using actors and use cases. Use cases are a set of actions, services, and functions that the system needs to perform. In this context, a "system" is something being developed or operated, such as a web site. A use case diagram is a dynamic or behavior diagram in UML. Use case diagram examples in Lucidchart Use case diagrams are visual representations of written use case scenarios. A Hybrid 0d–1d Model for Cerebral Circulation and Cerebral New Use Case Diagram with Example . Purpose: Two alternative examples of business use case diagram for a Restaurant - external and internal business views of a restaurant.