Image processing restriction information that defines time of day restrictions of a first function and time of day restrictions of a second function is stored in a memory unit. An image processing request for image processing of one of the first and second functions is received. Based on time managed by a time management unit, a time of the image processing request and the image processing restriction information, an image processing restriction corresponding to the first function or the second function is determined based on the received image processing request for image processing of the corresponding function. An image processing restriction is performed based on the determining of the image processing restriction corresponding to the first function and the determining of the image processing restriction corresponding to the second function.