The 'Use Case Diagram' supports two unique diagram constructs: a 'Use Case (Action)' and a 'Performer (Asset).' Each diagram construct is described in more detail below:

• Use Case (Action)

  In the system model, an Action entity is used to represent a 'Use Case' construct. In the diagram, this construct is represented as an oval and contains the name of the 'Use Case.'

  

• Performer (Asset)

  In the system model, an Asset entity is used to represent a 'Performer' construct. In the diagram, this construct is represented as a stick figure with the name of the 'Performer' underneath.