Five types of diagrams and Applications in UML

In general, UML has ten types of model diagrams, and ten types of diagrams can be divided into five categories:

1. use case diagram

It is used in the requirement analysis stage to describe the user's needs, who is using the system, and what functions the system performs, and emphasize who is using the role.

2. static diagram

Class diagram: A class is a static view that describes the classes in the system and the relationships between classes. Class diagrams are used to describe the class model, system design, and code implementation.

Object graph: an instance of a class graph that describes the objects and relationships that the system may contain at a certain time point. An object graph is not an actual class. It describes the relationship between objects rather than between classes. And the object has a lifecycle, so the object graph can only exist in a certain period of time.

Package diagram: provides a high-level overview of requirements and design to describe the layered structure of the system.

Three behavior Diagrams: Describes the system behavior in terms of system structure and behavior through the state chart, activity diagram, sequence diagram, and collaborative plot.

Activity diagram: describes the activities required by the use case and the constraint relationships between the activities. This helps you identify parallel activities.

Status chart: it is a supplement to the class chart to describe the transfer between all possible States and States caused by various events, state transfer can be accompanied by an action that indicates what the system will do when the transfer occurs.

4. Interaction Diagram

Sequence diagram: Describes the interaction process between objects in chronological order.

Collaboration diagram: similar to the sequence diagram, it describes the objects in the system and their communication relationships.

5. Implementation Diagram

Component diagram: used to display the organization and dependency between a group of components

The component diagram describes the main functions of a system from the perspective of software architecture, such as subsystems, classes, packages, and components. The most important thing to use components is reuse.

Deployment diagram: the configuration diagram describes the physical configuration and system architecture of hardware and software in the system.

In the process of software development, we must make full use of the static and dynamic modeling mechanisms of UML.

From the perspective of applications, when designing a system using an object-oriented method, we first need to describe the requirements, and then establish a static model of the system based on the requirements to construct the system structure; the third step is to describe the behavior of the system. The models created in step 1 and Step 2 are static, including the use case diagram, class diagram (including package), object diagram, component diagram, and configuration diagram, it is a static modeling mechanism of the standard modeling language UML. The model created in step 3 can be executed, or indicates the time sequence status or Interaction relationship during execution. It consists of four diagrams, including status chart, activity chart, sequence chart, and ing. It is a dynamic modeling mechanism of the standard Modeling Language (UML. Therefore, the main content of the standard modeling language UML can also be summarized into two categories: Static Modeling Mechanism and dynamic modeling mechanism. (See http://baike.baidu.com/view/23396.htm)