UML model elements
In the Project Explorer view, model elements appear under the model or the model element to which they belong. You can add, modify, sort, group, and filter model elements in models to provide details about the system and to make the model easier to understand.
All model elements have properties, such as a name. Other features, such as attributes and operations that belong to a class, can further define some UML model elements.
The following table describes the common types of model elements.
| Type of model element | Description |
|---|---|
| Structural model elements | These elements model the static parts of a system. Some examples include classifiers such as actors, classes, components, information items, and nodes. |
| Behavioral model elements | These elements model the dynamic parts of a system. Typically, you find behavioral model elements in state machine and interaction diagrams. Some examples include activities, decisions, messages, objects, and states. |
| Organizational model elements | These elements group model elements into logical sets. A package is an example of an organizational model element. |
| Annotational model elements | These elements provide comments and descriptions. Notes® and constraints are examples of annotational model elements. |
Classifiers
In UML diagrams, the term classifier is used to categorize a group of model elements that have similar structural features, which include attributes and associations, and similar behavioral features, which include operations and methods.
The term classifier refers to a concept that applies to not only a specific UML model element, but to all classifiers.
Classifiers can have unique presentation options, can have constraints, can be derived, can be stereotyped, and can have a number of tagged values. For example, in UML models, classes and data types have different purposes; however, they are both classifiers because of their similar structural and behavioral features.
A classifier's compartments are visible or hidden by default depends on the type of classifier. For example, when you create a class, by default, both the attributes and operations compartments are visible; however, when you create a data type, by default, the compartments are hidden.
- Actors
- Artifacts
- Classes
- Collaborations
- Components
- Enumerations
- Data types
- Information items
- Interfaces
- Nodes
- Roles
- Signals
- Use cases