Recently with the advent of the information technology and the wide spread use of the Internet, new user oriented production and logistic systems, such as the Supply Chain Management System, have been required in order to cope with the drastic and continuous changes on the markets and users' preferences. To achieve this purpose, the companies need to mutually integrate their database systems with heterogeneous requirements. Autonomous Decentralized Database System (ADDS) is proposed as a system architecture in order to realize assurance when distributed database systems with heterogeneous requirements have to coexist in a common environment without violating each other characteristics. In this system architecture, a loose consistency management technology is proposed in order to let each database to autonomously update its own information while preserving the consistency of the total system. The autonomy of each site can be achieved by defining a data attribute, Allowable Volume ( A V), at each DE within which each site can update. Moreover, a background coordination technology, performed by an autonomous mobile agent (MA), permits that the sites can coordinate and cooperate each other. The MA moves around the sites in order to continuously adjust and allocate A V by negotiating with them under evolving situations. Furthermore, the effectiveness of this assurance systems is experimentally shown in the supply-chain management system model by simulation.