Working With Model Items and Diagrams > Working with diagrams > Diagram types > Composite structure diagram
Composite structure diagram
The Composite Structure Diagram is a UML 2.0 diagram that is useful for modeling the decomposition of structured Classes, Data Types, Interfaces and Signals through Parts and Ports, and the flow of information between those Parts and Ports. The Composite Structure Diagram provided with Modeler includes support for IO Flows, which is a SysML extension to UML information flows. An important difference between a Composite Structure Diagram and a Class Diagram is that a Composite Structure Diagram shows decomposition in context.
The Composite Structure Diagram replaces the System Architecture Diagram. For information about using the System Architecture Migration Utility to migrate your System Architecture Diagrams to Composite Structure Diagrams, see Overview of system architecture diagram migration.
For information about Class Modeling or Composite Structure Diagrams in Modeler, see Overview of class modeling.
You can create a Composite Structure Diagram through the context menu of a Package: right-click the Package, and select New > UML > Structure > Composite Structure Diagram. Alternatively, if you have configured to display New Diagram in the Quick Access Toolbar, then select New Diagram > Composite Structure Diagram. You can also create a Composite Structure Diagram through the context menu of a Class, Data Type, Interface or Signal: right-click the item, and select New > Composite Structure Diagram.
You must use a Composite Structure Diagram to create the following Model items:
IO Flow
Role (as Part or Port scoped Part or Port)
The following sections provide information about how a Composite Structure Diagram is used in the model. For more information about an item, property or model part, click it.
Shows these dictionary items
Like most diagrams, a Composite Structure Diagram can show variability items and relationships. See Overview of variability items and relationships on diagrams.
For most diagram symbols, you can change the presentation of the symbol through the Style view options (See Style view options - all diagrams), and change the showing of Stereotypes and Tag Definitions through the Stereotypes view options ( Stereotypes view options for a symbol - all diagrams). When a symbol has additional view options for changing its presentation, this icon is shown - to see how the view options can change the presentation, click the icon.
Actor
Attribute (as Part or Port)
Association
Class
Comment
Constraint
Data Type
Dependency
Interface
IO Flow
Role (as Part or Port)
Signal
These items (which are not documented in the reference topics) can also appear on a Composite Structure Diagram:
• Frame Box - provides a way of adding a box or background image to the diagram.
• Note - provides a way of adding text to the diagram.
• Note Link - links a Constraint, Comment or Note to an item on the diagram.
Properties
A Composite Structure Diagram has these properties:
• Name
• Type
Owned by
Class
Data Type
Interface
Model
Package
Signal
Used in these parts of the model
Class Model
Can be linked to these dictionary items
Stereotype
* 
Like other diagrams in a Model, a Composite Structure Diagram can be linked to an Activity Partition, Comment, Frame Box, General Node, General Flow, General Flow Diagram Node, Constraint (applied), General Flow Diagram Flow or Swimlane.