Start-stop system and method for controlling the same

ISG system and method for controlling the ISG system, comprising determining whether pre-conditions for an engine stop in a motor control means are met, when an engine is in operation, determining whether the engine can be stopped when they meet the preconditions of the engine stop , determining whether the engine stop conditions are satisfied, if the engine can be stopped, stopping of the engine which is in operation when the engine stop conditions are met, determining whether key start conditions are satisfied when the engine is stopped, determining whether a restart is possible if the keys start conditions are not satisfied, determining whether conditions are satisfied for the restart, when the restart is possible, and restarting the engine, when the restart conditions are met.