The main function of a fire alarm system is to detect the start of a fire as early as possible and notify the occupants. However, a fire alarm system alone cannot ensure the safe occupancy of a building. For it to be fully effective, a fire alarm system must be used in conjunction with a fire safety plan and emergency measures.
A fire alarm system may consist of the following components: control panel, manual triggers, fire detectors (smoke detectors and heat detectors), audible alarms, visual alarms, electrical monitoring systems to supervise pressure, flow, and valves in the case of buildings protected by sprinklers, annunciators to indicate the origin of the alarm, emergency telephones, and other devices for communication between the control panel and different parts of a building.