You are required to appoint a competent person to supervise servicing of the system. This person needs to have authority to ensure that the test and maintenance work necessary to maintain the system in the correct operational mode can be undertaken.
Emergency lighting is lighting for an emergency when the main power supply is cut and any normal illumination fails. The loss of mains power could be the result of a fire or a power cut where the normal lighting fails. This may lead to sudden darkness and a possible danger to the occupants, either through physical danger or panic.