Which component alerts that the fire alarm system has been activated?

The component that alerts individuals that the fire alarm system has been activated is the alarm notification device. This device is specifically designed to emit sounds, visual signals, or both, to inform occupants of a building that there is a potential fire emergency requiring immediate action. Common examples of alarm notification devices include bells, horns, and strobe lights, which are crucial for ensuring that all occupants are aware of the situation and can evacuate the premises safely.

The control panel serves as the brain of the fire alarm system, processing inputs from various sensors and initiating responses, but it does not directly alert individuals in the environment. The trouble alarm indicates a fault within the fire alarm system itself, which does not signify a fire event. The decision support system, while valuable for analyzing data and assisting in firefighting and emergency response, is not a direct alert mechanism for fire alarms. Therefore, the alarm notification device is the primary component responsible for alerting individuals when the fire alarm system is activated.