In situations of economic instability, high taxes, and reduced production time, each manager needs to reduce delay in production, flexibly respond to any changes in the market, and take account of new trends in market development.One way of resolving this matter is to introduce into enterprises an information system that would help curtail the documentation preparation time and improve its quality, which will ensure prompt decision making at any stage of the production cycle, a flexible organizational structure, and minimum delay.A special department has been created at the affiliate corporation Central Design Office of Oil Equipment (CDOOE) to design a corporate information system (CIS).The life cycle (LC) of information systems, i.e., the totality of repetitive phenomena over the whole lifetime of the information system, consists of several parts, viz., generations, releases, and phases. In the LC of a software there exist almost always the following phases:-analysis of system requirements; -designing; -programming (debugging); -maintenance (putting into operation). There are many ways of organizing the life cycle (LC) of information systems. The main LC organizing models are cascade, iteration, and spiral.In developing the CIS a spiral model was chosen, in which the LC of the information system consists of several turns. In each turn the system passes through all of the major phases (requirements analysis, designing, pro~anuning and debugging, introduction and maintenance). The product of each tum is not the ware itself, but its prototype, by working with which the user can determine new system requirements more accurately. In the last turn of the spiral the information system meets user's requirements most fully.The first stage in CIS building is predesign study of the existing design and control system in order to understand how this system works. Since developers and users of information systems are, as a rule, far from each other, for finding a common language it is extremely important that this work be carried out carefully and that an understanding of the existing system (design, control, planning, accounting, etc.) be gained with a certain level of reliability.A modular-hierarchical approach, in which individual representations of the system are examined at various abstract levels, was applied, and this helped understand how the system as a whole works. Out of a whole array of representations that describe the system, the functional, informational, and morphological (o~anizational) ones were chosen. The internal functional representation of the system generally means the functional model of the system and makes use of either simple structural models or special notations like IDEF0, Petri networks, etc. In modeling the production process, the affiliate corporation Central Design Office of Oil Equipment (CDOOE) used the notation IDEF0.The model of the system in this notation is presented as a multitude of diagrams arranged hierarchically. Each diagram describes the system at a specified level of abstracti...
