A design support method of inspecting control on an image forming apparatus based on a simulation result of operation control on a virtual device which is modeled to simulate operation of the image forming apparatus includes the steps of referring to control definition information for determining whether an operation request is proper with respect to a virtual device for which the operation request is input, in accordance with an operating state of the virtual device, and determining, based on the control definition information referred to in the referring step whether operation of the virtual device can be performed.