Deployment Diagram (DPD)

Purpose

A deployment diagram (DPD) shows a configuration of run-time processing elements and the components and objects that run on them. You can use a deployment diagram, for example, to show the configuration and routing of components and objects in a distributed system.

Example deployment diagram

A sample deployment diagram.

Control panel

The control panel of the deployment diagram.

Node

A node can represent any computational element, but generally represents a piece of hardware.

Label

type

Node instance

A node instance represents a specific computational element.

Node instances can contain component instances, objects, and active objects. On the diagram, place the contained elements on top of the node instance. Use Check|Contents to ensure that node instances contain only appropriate elements.

Label

name:type

Connection

Communication paths among the nodes are shown as connections (solid lines).

Label

connection-type

Component

A component generally represents an executable piece of the system, such as a software system. In modeling a business, however, a component might represent reports, forms, or other business documents.

Label

type

Component instance

A component instance represents a specific component.

Component instances can contain objects and active objects. On the diagram, place the contained elements on top of the component instance. Use Check|Contents to ensure that component instances contain only appropriate elements.

Label

name:type

Interface

An interface represents the externally-visible operations of a component. It is connected to a component and labeled with the name of an interface class that is defined in a class diagram.

Label

interface-class

Dependency

You draw a dependency (a dashed arrow) between two components or interfaces to indicate that changing the destination component or interface might require a change in the source component or interface.

You can attach stereotypes, such as <<copy>> or <<derived>>, to a dependency. See Working With Items.

DPD only

In a deployment diagram, the <<becomes>> stereotype is useful.

• Draw a dependency with a <<becomes>> stereotype from a component in one node dependency to the same component in another node dependency to show that the component migrates from one node to the other. Draw a dependency with a <<becomes>> stereotype from an object in one component instance to the same object in another component to show that the object migrates from one component instance to another.

Label

No label.

Object

An object represents an instance of a class.

Objects can contain objects and active objects. On the diagram, place the contained elements on top of the object. Use Check|Contents to ensure that objects contain only appropriate elements.

Label

name:type

The type must be a class defined in a class diagram.

Active object

An active object represents an instance that owns a thread of control and can initiate control activity. For example, processes and tasks are active objects.

Active objects can contain objects and active objects. On the diagram, place the contained elements on top of the active object. Use Check|Contents to ensure that active objects contain only appropriate elements.

Label

name:type

The type of an active object does not have to be defined in a class diagram.