PURPOSE: To restrict influence to be exerted upon the whole system to its minimum by removing a fault generated when a processor runs down in a multiprocessor system having a shared link in a shared memory.

CONSTITUTION: A connection changing procedure for forward links 20 to 23 and back-ward links 30 to 33 is previously regulated as moving operation for acquiring and returning elements 11 to 13 constituting the link structure in the shared memory. The operation of the processors is monitored during the operation of the system, and at the time of detecting processor down, the stored connection changing procedure is compared with the status of the link structure at that time, a section in which moving operation is executed by the down processor is specified and link connection among the elements in the section of the moving operation is changed to repair the line structure.