Component Diagram

A Component diagram illustrates the pieces of software, embedded controllers and such that make up a system, and their organization and dependencies.

A Component diagram has a higher level of abstraction than a Class diagram; usually a component is implemented by one or more Classes (or Objects) at runtime. They are building blocks, built up so that eventually a component can encompass a large portion of a system.

You generate Component diagram elements and connectors from the Component pages of the Toolbox.

Example Diagram

This diagram demonstrates a number of components and their inter-relationships.

Assembly connectors connect the provided interfaces supplied by Product and Customer to the required interfaces specified by Order. A Dependency relationship maps a customer's associated account details to the required interface Payment, also specified by Order.

Component Diagram Element Icons



See also

Packages are used to organize your project contents, but when added onto a diagram they can be use for structural or relational depictions.


A Packaging Component is an element that appears very similar to a Component in a diagram but behaves as a Package in the Project Browser.

Packaging Component

A Component is a modular part of a system, whose behavior is defined by its provided and required interfaces.


A Class is a representation of a type of object that reflects the structure and behavior of such objects within the system.


An Interface is a specification of behavior (or contract) that implementers agree to meet.


An Object is a particular instance of a Class at run time.


Ports define the interaction between a classifier and its environment.


The Expose Interface element is a graphical method of depicting the required or supplied interfaces of a Component, Class or Part, in a Component or Composite Structure diagram.

Expose Interface

An Artifact is any physical piece of information used or produced by a system.


A Document Artifact is an artifact having a stereotype of «document».

Document Artifact

Component Diagram Connector Toolbox Items



See also

An Assembly connector bridges a component's required interface (Component1) with the provided interface of another component (Component2), typically in a Component diagram.


A Delegate connector defines the internal assembly of a component's external Ports and Interfaces, on a Component diagram.


An Association implies that two model elements have a relationship, usually implemented as an instance variable in one or both Classes.


A source object implements or Realizes its destination object. Realize connectors are used in a Use Case, Component or Requirements diagram to express traceability and completeness in the model.


A Generalization is used to indicate inheritance.