One of the most used UML diagrams is the use-case diagram. It is a behavioral model. It helps us to capture the requirements of the system. Use-case diagrams describe the high-level functions and scope of a system. These diagrams also identify the interactions between the system and its actors.
Components:
actor: An actor represents a role of a user that interacts with the system that you are modeling. The user can be a human, an organization, a machine, or another external system. It is represented by sticky mam.
We use nouns to name the actors.
use-case: A use case describes a function that a system performs to achieve the user’s goal. A use case must yield an observable result that is of value to the user of the system. We use verbs.
relationships: In UML, a relationship is a connection between model elements. A UML relationship is a type of model element that adds semantics to a model by defining the structure and behavior between the model elements.
Types of relationships:
- Association
- Undirected association
- Generalisation
- Dependency
- Realization
Sample use-case diagram for ATM