Package and component diagrams

Instructor's Guide

introduction class diagrams use cases interaction packages state and activity discussion
Although classes may be considered the building blocks of object-oriented applications and frameworks, they are usually not the units of deployment nor the units of reuse. See  [Szyperski97]. Rather, packages and components may be considered as such.

slide: Package and deployment diagrams

A package diagram, depicted left, indicates the dependencies between packages, and possibly classes. Component or deployment diagrams depict the components, their exported interfaces and the dependency between components.

Although package and component diagrams are usually implementation-level diagrams, it seems advisable to take clustering and component packaging into consideration in the early stages of design.