PURPOSE: To partially cope with a failure or the like by unitizing respective system computers so as to disperse their functions, so that mutual communication of information can be carried out through a network connection.

CONSTITUTION: An instruction information system is divided into a base computer 1 for programming a master file and a schedule control computer 2 for programming a data file. By networking these computers, mutual communication of information is carried out, and on the other hand, selective production system computers (VMS) 3 which network with process work stations 5 being production lines are juxtaposed so as to network with the instruction information system. Since the respective system computers are unitized so as to disperse their functions and mutual communication of information is carried out through a network connection, partially coping with a failure or the like can be enabled.