1. An image formation apparatus comprising: a hypervisor for using a resource including a processor and a system memory to control simultaneously running a plurality of OSs (Operating Systems) including a host OS and at least one guest OS; a control firmware running on the host OS and responsible for controlling the image formation apparatus; a cooperation module operating on a same level as the hypervisor; and a free memory management module for managing a free memory space of the system memory that is not used by the host OS or a guest OS running simultaneously with the host OS, the resource including an image memory managed by the control firmware and adapted for image processing, the cooperation module being configured to: cooperate with the control firmware to obtain an available memory space of the image memory; associate a content of a job to be processed with a program running on one or more guest OSs required for that job; before starting the job, read a required guest OS into the available memory space of the image memory and cause the associated program to be executed; and restore a content of the system memory determined as not being used by the host OS and another guest OS to the image memory to allow the system memory to be used as a system memory for a newly run guest OS.