Abstract: The present invention provides a control system (10) for managing the supply of bottled gas to users (12), the system comprising: a gas cylinder system (14) having a gas cylinder (15) for receiving and distributing gas contained therein; a first electronic monitoring system (16) associated with said gas cylinder system (14) and operable to monitor parameters associated with said cylinder system (14); a second monitoring system (18) associated with one or more locations (A-F) in which said cylinder may reside and being operable to monitor the presence or absence of said cylinder within said one or more locations (A-F); and a computer system (20) in communication with each of said second monitors (18) for receiving information therefrom relating to the presence or absence of said cylinder system (14) in said one or more locations (A-F).