How many subsystems are there

• A. 3
• B. 5
• C. 6
• D. 4

Answer: (D)

Subsystems are the major functional blocks that together produce the system’s behavior. To determine how many there are, identify the distinct functions that must be performed for the system to work and recognize each as a separate block with a clear interface. In this case, the system is organized into four independent functional areas: one handles power and energy distribution, another covers control and coordination, a third provides the actual output or actuation, and a fourth handles safety, monitoring, and fault handling. Because these four areas operate as separate, non-overlapping blocks that collectively enable the system, there are four subsystems. Trying to count more would split a block that’s meant to act as a single functional unit, while counting fewer would merge distinct responsibilities that the design keeps separate.