Here are the key elements of a use case diagram:
- Actor: Represents a role that interacts with the system. Examples include employee, manager etc.
- Use case: Represents a discrete unit of functionality that provides value to an actor. Examples include add employee, generate payroll etc.
- Association: Connects an actor to a use case to show that the actor can interact with that use case.
Notations:
- Actor: Stick figure
- Use case: Oval
- Association: Solid line
- System boundary: Rectangle
5.2 Sequence Diagrams:
Sequence diagrams are interaction diagrams that detail how operations are carried out — what messages are sent and when. They are