Distributed information system

Until the late 70's information system technology (i.e., computers, communications network, etc.) had not been flexible enough to adjust itself to vario~s managerial styles, in particular to decentralized organizations. Computers were large and centralized; consequently, data bases and computing power could not be delegated to the end user. The rapid progress in the development of microcomputers and communications has brought technology to a state where management can subdue the hardware and software configuration to. comply to its managerial approach. Information systems which are less centralized than in the past are labelled Distributed Information Systems (DIS). A DIS is not necessarily a fully distributed system. It is an information system where the responsibility over some of its components has been delegated to end users. For instance, the requirement definition is performed by the user; the analysis, design, and programming are carried out by a central body; the routine operation is undertaken by the user; the insert of software changes and the upgrading of equipment is centrally managed. Such combinations of distributed and centralized activities are widely common. The major problems they raise are not technical but managerial how can management decide what activities are to be distributed, and how distributed activities can still be controlled. It can be observed that in parallel to the technological progress, the literature on DIS has passed through three generations. The first generation (the beginning of the 70's) focused on solving technical problems, e.g., how to connect computers