Some Notions of Decentralization and Coordination in Large-scale Dynamic Systems

In this paper, we shall discuss some notions of decentralization and coordination in the control of large-scale dynamic systems. Decentralization and coordination have always been important concepts in the study of large systems. Roughly speaking, decentralization is the process of dividing a large problem into subproblems so that it can be handled more easily. Coordination is the manipulation of the subproblem so that the original problem is solved. A great deal of literature is available dealing with these two topics, especially decentralization. In this paper, we shall discuss the various types of decentralization and coordination that have been used to control dynamic systems. Our emphasis will be to distinguish between on-line and off-line operations. This distinction is not, of course, unique. However, it helps to understand the results available by indicating the aspects of the problem which are decentralized. This discussion is informal and no attempt has been made to give precise definitions. Our main objective is to illustrate intuitively "what" is decentralized in the decision-making.