A use case diagram can identify the different types of users of a system and the different use cases
Creating Use Case Diagram for describing the behavior of the target system from an external point of view.
https://sourcemaking.com/uml/modeling-it-systems/external-view/the-elements-of-view/use-case-diagram
http://creately.com/blog/diagrams/use-case-diagram-tutorial/
To identify functions and how roles interact with them
For a high level view of the system – Especially useful when presenting to managers or stakeholders.
To identify internal and external factors.
Use case diagrams consist of 4 objects.
Actor
Use case
System
Package
· Dependency, generalization, and association relationships
Generalization of an Actor
Extend Relationship Between Two Use Cases
Include Relationship Between Two Use Cases
Examples
http://www.uml-diagrams.org/use-case-diagrams-examples.html
