System boundary boxes: A box that sets a system scope to use cases. In complex diagrams, it is important to know which actors are associated with which use cases. Use cases: Horizontally shaped ovals that represent the different uses that a user might have.Īctors: Stick figures that represent the people actually employing the use cases.Īssociations: A line between actors and use cases. Here are all the shapes you will be able to find in Lucidchart: You can use this guide to learn how to draw a use case diagram if you need a refresher. The notation for a use case diagram is pretty straightforward and doesn't involve as many types of symbols as other UML diagrams.