An information processing system includes a receiving unit that receives user operation; a setting unit that holds association information in which pieces of necessity information each indicating necessity of a shutdown process indicating a process required for stopping power supply to a corresponding device are associated with a plurality of devices, respectively; a first instruction unit that instructs a target device for which the power supply is to be stopped to perform the shutdown process when the receiving unit receives operation to stop the power supply and the target device requires the shutdown process based on the association information; and a second instruction unit that instructs a power supply control device that controls execution or stop of the power supply to the target device to stop the power supply to the target device when the shutdown process of the target device is completed.