Compose and Analyze a System

A system is a composition of different elements that serves a goal that cannot be achieved by any of the elements alone. The elements of a system can be mechanical parts, electrical circuits, computer hardware, and software. A system solution consists of a set of elements as well as their characteristics and properties. System Composer™ enables you to create architecture models using structural and behavioral diagrams that all act on the same underlying model. This way, you ensure that a change in one diagram is reflected in the other diagrams, resulting in a consistent system model that you can share.

With System Composer, you can:

  • Create structural models using hierarchical functional, logical, and physical architecture diagrams

  • Support specific architectural requirements by customizing architectural types

  • Validate behavior, and refine and elaborate requirements

  • Perform static analysis and trade studies to optimize system architectures

Consider a mobile robotic system where a computer sends a target location to the robot wirelessly. This system has two primary components: the computer and the robot. You represent them in System Composer using two Component blocks.

To capture specifications relevant to the problem, you can add non-visual properties to a component. For example, if the total power consumption of the system is a concern, a Power Consumption property is necessary. You can add this property to an electrical component using a stereotype. A stereotype adds properties to components, ports, and connectors.

Connections are essential in describing a system as a network of components. In System Composer, you define ports on each component and connect them.

You can define an interface to fully specify a connection and its associated ports. An interface can consist of multiple data elements with various dimensions, units, and data types. To enable consistency checking when connecting a port, you can also associate interfaces with unconnected ports during component design.

Requirements are integral to the system engineering process. Some are related to the functionality of the overall system, and some are nonfunctional. Some requirements of the overall robot system could be:

  • Total power consumption

  • Time between issuing a command from the computer and completing the motion of the robot arm

  • Precision in positioning the arm

To allocate and trace requirements with system elements,System Composer fully integrates with Simulink® Requirements™

Often, system requirements are broken down into requirements for each component. Component requirements evolve during design.

Robot requirements — maximum speed and sensitivity of proximity sensors — point to subcomponents motors and sensors. You can represent these subcomponents by decomposing the component.

You can associate components with requirements at any level of the system.

Sometimes an overall analysis of the system is necessary to verify requirements or to serve as requirements for the design of other systems. An example would be a box to house the robot system in extreme conditions. Customizing model elements using nonfunctional properties such as weight or temperature sensitivity enable such analyses.

The next step in system design is designing the actual behavior of the components in Simulink. Link System Composer components to Simulink models to trace architectural design to behavioral design.

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