PTC introduced the System Architecture Diagram to cover the short comings of previous versions of UML for the real-time environment. Now that UML 2.0 has introduced the Composite Structure Diagram , the System Architecture Diagram is no longer required. As such, the System Architecture Diagram remains in Modeler for backward compatibility, but it will not be further developed in Modeler: for example, you cannot apply iconic Stereotypes to the System Architecture Diagram symbols.

We recommend that you now model your system architecture using Composite Structure Diagrams, in accordance with UML 2.0. To help you migrate your System Architecture Diagrams to Composite Structure Diagrams, Modeler includes the System Architecture Migration Utility.

For information about Composite Structure Diagrams, see Composite structure diagram symbols.

The System Architecture Model allows you to define architectural solutions to the level of bus, board and disk. A series of System Architecture Diagrams describes the physical distribution of the system, showing processing and interface nodes plus the connections between them. Actors initiate processing activity in the System Architecture Model by sending event messages to subsystems and interface devices.

You structure your model using subsystems and frame boxes. A subsystem contains components of the system architecture, and can be indefinitely nested. A frame box groups related elements visually on your diagram.

You plan your system's architecture by assigning abstract design types to physical components. In particular you set up a board layout using a board type. This layout identifies board features, processors, memory devices and i/o devices, together with their associated design types. In addition to types of board and board feature, you can define types of disk, multidrop bus, point-to-point connection and interface device.

Components of the system architecture communicate with each other to carry out processing requests. The System Architecture Diagram assigns links according to the items being connected. Actors make external connections to subsystems and interface devices. A drop connects components to a multidrop bus. All other items are linked by point-to-point connections

Modeler allows you to manually build a System Architecture Diagram or you can add one item and then automatically populate the diagram with related items and associations.

Subsystems can be the initial building blocks for State Diagrams and Activity Diagrams in the System Modes Model.

See System architecture model to open the System Architecture Model reference topic.

A System Architecture Diagram includes the following elements: