A management system and a management method according to the invention calculate, on the basis of collected weather information, an operation record of a device, a state value and an acceptable range set for an area where the device is installed, and power-suppression-time during which electric power is suppressed, change-time during which the state value of the area is changed in response to the power-suppression-time by operations of the device, generate, using the calculated change-time, a control-schedule for controlling the device, and control the device. This enables reduction of electric power usage with the state value set for the area where the device is installed kept within the range in accordance with the power-suppression-time.