A Subsystem is typically a large, encapsulated block within a larger system.
You can convert any Block to a Subsystem if you decide that the appropriate Block is decomposed. It may be called a system (i.e., Power Subsystem, Brake Subsystem, Lightening Subsystem).
In SysML, properties and operations of the Block are public. Visibility representation literals, like +, #, ~, -, are not displayed in the Containment tree or in the element symbol on a diagram.
Converting a Block to Subsystem
To convert a Block to Subsystem
- Right-click a Block.
- Select Refactor > Convert To > More Specific > Subsystem.
The Block is converted to a Subsystem.