Models in UML are constructed from elements such as Classes, Objects, Interfaces, Use Cases, Components and Nodes, each of which has a different purpose, different rules and different notation. Model elements are used at different stages of the design process for different purposes. For example,
|•||During early analysis, Use Cases, Activities, Business Processes, Objects and Collaborations are used to capture the problem domain|
|•||During elaboration, Sequence diagrams, Objects, Classes and State Machines are used to refine the system specification|
|•||Components and Nodes are used to model larger parts of the system as well as the physical entities that are created and deployed into a production environment|
Behavioral Diagram Elements
Behavioral diagrams depict the behavioral features of a system or business process. Elements that can appear on Behavioral diagrams include Activity, Interaction, Lifeline, State Machine and Use Case.
Structural Diagram Elements
Structural diagrams depict the structural elements composing a system or function. Elements that can appear on Structural diagrams include Class, Component, Interface, Node and Package.