Modeling the physical subsystem
Using block diagrams and internal block diagrams to model the physical subsystem
The physical subsystem represents the physical structure of the system in terms of the equipment installed within the system. The figure on the right represents the block diagram of the physical subsystem and determines its composition, consisting of modules such as valves, tanks and devices, among others.
While the figure above showed the relation of the physical subsystem to other modules, the figure on the right displays the internal composition of the physical subsystem by means of a SysML internal block diagram. Here, the structure of the subsystem is clearer compared to the previous figure. The ports of the sub modules of the physical subsystem are SysML flow ports, which indicate the flow of a specific entity. For example, ElectricPower represents an electric flow that passes between several of the physical subsystem's modules. Similarly, other flow ports are typed with FS_FLUID, Pressure, and so on, representing the flow of a fluid or pressure respectively.