UML Elements

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.

This topic provides an introduction to elements defined by UML, which together compose the backbone of modeling. Most conceivable modeling elements are stereotypes or extensions of the elements introduced in this topic.

  • 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.

UML elements can be divided into two categories: those used on Behavioral Diagrams and those used on Structural Diagrams. This basic set can be extended almost without limit using Stereotypes and UML Profiles.