An image forming apparatus activates target devices including connected devices and internal devices, and executes a requested process. The image forming apparatus includes an acquiring unit configured to acquire information pertaining to the connected devices, information pertaining to a startup method of the image forming apparatus, and information pertaining to maximum usable power of a power supply unit of the image forming apparatus; a specifying unit configured to verify what the target devices are and specify a corresponding activation pattern based on the information acquired by the acquiring unit, wherein the corresponding activation pattern is specified among plural activation patterns that have been set in advance, each of the plural activation patterns defining activation timings of the target devices; and an activation control unit configured to control activation of the target devices in accordance with the corresponding activation pattern specified by the specifying unit.