Which description best contrasts manual and automated control strategies in a production facility and highlights typical failure modes of automation?

• A. Manual control requires operator intervention; automated control uses setpoints and feedback; potential failures include sensor drift, actuator stuck, communication loss, and cyber vulnerabilities; redundancy and testing are necessary.
• B. Manual control requires no operator input and uses fixed setpoints.
• C. Automated control makes decisions randomly.
• D. Manual and automated controls are identical in their failure modes.

Answer: (A)

In production systems, manual control means a human operator makes the adjustments based on what they observe, while automated control uses sensors, a controller, and actuators to maintain the desired state through feedback. The strength of automation is precision and speed, but it brings specific failure modes: sensors can drift or become biased, giving the controller bad data; actuators can stick or jam, preventing the right action from being executed; communication links between sensors, controllers, and actuators can fail, breaking the feedback loop; and networked systems can be vulnerable to cyber threats that allow unauthorized changes or disruptions. To guard against these issues, redundancy and thorough testing are essential, along with regular calibration and health checks.

The other descriptions don’t fit because manual control does require operator input, automated control does not decide randomly, and the failure modes of manual and automated systems are not identical.