Use case model
The Use Case Model comprises a set of Use Case Diagrams. Use cases model how a system is going to be used in a given context, giving you an overall picture of the system from a user's point of view.
For information about Use Case Modeling in Modeler, see Overview of use case modeling.
You can view the Use Case Model part of a model through the Use Case Model folder in the Relationships pane.
The following sections provide information about the item and diagram types that are used in the Use Case Model. For more information about a diagram or item, click it.
Uses these diagrams
Defines and uses these dictionary items
Actor
Constraint
Generalization
Increment
Use CaseNote that this icon 
indicates that the item can appear on Use Case Diagrams.
indicates that the item can appear on Use Case Diagrams.