UML Learning: Use case diagram

The concept of a use case diagram

A use case diagram is a diagram that describes a use case, a participant, and the relationships between them.

Role of use case diagram

The use case diagram describes the requirements of the information system from the user's point of view and analyzes the function and behavior of the product.

The use case diagram defines and describes the external visible behavior of the system, which is an important basis for analysis, design and assembly testing.

Let the user participate in the prophase system analysis and design.

Participants ' concepts (actor, performer, activists)

A contributor is an object that is outside the system but interacts directly with the system. For example, there is a specific concept for the participants, as shown in the figure:

Participants use human symbols to indicate that the actor's role name (not the name) is marked below the human symbol, for example: