PURPOSE: To attain a decentralized processing system having high extending performance by forming the software with each object defined as a unit and handling a data base, a knowledge base, etc., in an integrated way with all object made resident in a main storage.

CONSTITUTION: The computer systems 11i1 - 11in are connected to each other via a local area network LAN 12 and also communicatable with the computer systems 11j1 - 11jn which are connected to a LAN 14 via a wide area network WAN 13. The data, the knowledge, and the procedure included in the system 11i1 consist of the units of objects which are all resident in a main storage. That is, the system 11i1 consists of the objects 15i1 - 15in in regard of all functions of the system. Thus a decentralized processing system having high extending performance can be obtained.