PURPOSE: To effectively use a resource and to avoid extreme slow processing speed due to slow down, by performing the detection and release of slow down at each resource through the management of types of resources.

CONSTITUTION: A resource number is determined and managed at each type of resource and the detection and release of slow down is made at each resource. For example, when a program is started, a required slow down mode SDMF is selected with a central processor CPU1, a request block RB is linked to a start possible matrix RAQ of a memory M2 when the SDME is turned off, a resource stored in a control block CB of a memory 1 is acquired for processing. When the SDMF is turned on at the program start, the request block RB is linked to a processing queve WQ. When the processing of the program is finished, the resource S acquired at the start is returned to the control block CB to turn off the slow down mode SDMF.