An information management system includes a storage medium storing position error information of the rotation sensor obtained based on information of the back electromotive force and output information from the rotation sensor in an inspection process in which a back electromotive force is measured by mechanically driving the rotary electrical machine after the rotary electrical machine and the rotation sensor are assembled, wherein the storage medium is provided in a state capable of being read via communication when a control device controlling the rotary electrical machine is assembled with the rotary electrical machine.