The previous views model the concepts in the application from a logical viewpoint. The design views model the design structure of the application itself, such as its expansion into structured classifiers, the collaborations that provide functionality, and its assembly from components with well-defined interfaces. These views provide an opportunity to map classes onto implementation components and expand high-level classes into supporting structure. Implementation diagrams include the internal structure diagram, the collaboration diagram, and the component diagram.
The primary diagram is the class diagram, which is the foundation for modeling objects, the source for code generation, and the target for reverse engineering.
The object diagram illustrates objects rather than classes. The object diagram can be used to test or simply understand a class diagram. However, most CASE tool vendors do not support it at this time.
For modeling object interactions, the logical view includes sequence and collaboration diagrams. These are two very similar views for identifying object interfaces and communication.
To model internal object behavior, the statechart diagram provides a look at how an object reacts to external stimuli and manages internal changes.
The activity diagram describes processes including sequence, conditional logic, and concurrency. This diagram is like a flowchart, but it has been enhanced for use with object modeling.