UML use case diagram

I. Definition

Use case diagram describes the system function model diagram observed by external users of the system. external users are called "Participants", and system functions are presented in the form of "use cases, it is mainly used to model the functions of systems and subsystems.

Ii. Basic Content 1. Participants)

A participant is not a specific person, but a role outside the system in the use of the system or in interaction with the system. Therefore, participants can be people, things, time, or other systems.

2. Use Case)

Use Cases are system functions visible to participants

3. Boundary

Displays the functions of a system or subsystem and marks the boundaries of the system or subsystem.

4. Notes

Provide text description

Iii. Relationship 1. Association)

Describes the relationship between participants and use cases.

2. generalize)

Describes the abstract and specific relationships between participants and use cases.

3. Include)

Describes the relationship between use cases and use cases. A complex function usually consists of several small functions.

4. Extended)

Describes the relationship between the use case and the use case. After a function is executed, additional operations may be performed.

4. use case diagram

See http://www.cnblogs.com/ywlaker/p/6077201.html. Complete example:

UML use case diagram