What is a Control and Information Architecture ?


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The Control and Information Architecture is one of three basic components of any enterprise (the other two are the Production Facilites, and the People/Organizational Architectures.) In the PERA Model, it is usually depicted on the right, although it has an interface with the "Facilities" of the enterprise, so the diagram might actually be better represented if it were "wrapped around" into a sphere.

The term "architecture", as used in this website, refers not only to bricks and mortar structures, but the structure via which material and data move through maufacturing facililites and organizations.

The Control and Information Architecture may be represented by a series of "Architecture" diagrams, beginning with the Control and Information Philosophy Diagram, and progressing through increasing levels of detail, to Network Diagrams (primarily representing physical network structures), Entity Relationship Diagrams (primarily representing logical structures), and ultimately to wiring diagrams, program dataflows, etc.

The evolution of Control and Information Architectures, and the ways of representing them, is an important aspect of the Computer and Communication Revolution that has occurred in the latter half of the the 20th century.

The purpose of the Information Architecture is to graphically represent the communication, processing and storage of information as it moves through the enterprise. Like the structural analysis of buildings, or the modelling of chemical process plants, the Information Architecture can then serve as the basis of mathematical models of information flows.

The Control and Information Architecture Diagram (CIAD) is a schematic representation of the information processing nodes (computer systems) and communications (networks) which comprise the Control and Information Systems of the Enterprise. CIADs are high level drawings similar to the "Process Flow Diagrams" (PFDs) used in process industries, or Mechanical Flow Diagrams (MFDs) used in descrete manufacturing. In much the same way that the PFD or MFD shows major material flows and major processing equipment and storage facilities, the CIAD shows major information flows, information processing, and storage systems.

Like the PFD, the CIAD should be developed during the Conceptual Engineering Phase at roughly the same time as the PFD or MFD. Depending on the complexity and the state of definition of the enterprise, the CIAD may be presented at various levels of detail ranging from very "high level" (e.g. a half page representation of a whole enterprise) to a much more detailed version showing each server farm and block of users. Click here for a more detailed description of CIADs and the rules for drawing them.

Control and Information Network Diagram (CIND) is a schematic representation of the information processing nodes (computer systems) and communications (networks) which comprise the Control and Information Systems of the Enterprise. CINDs are more detailed drawings. In much the same way that the "Piping and Instrumentation Diagrams" (P & IDs) used in process industries, or manufacturing industries show major material flows and major processing equipment and storage facilities, the CIND shows major information flows, information processing, and storage systems. Click here for a more detailed description of CINDs and the rules for drawing them. The CIND is developed during the Preliminary Engineering Phase in parallel with the P&IDs.

Sequence Control Flow Charts are developed to convey the continuous (regularory loops), descrete control logic (interlocks), and sequence control logic (sequence of operations, both manual and automatic). These are developed during Preliminary Engineering Phase in parallel with the P&IDs and CINDs. There are a large number of diagram produced during the Detail Engineering Phase to develop the next level of detail from the CIND. These include:

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The Control and Information System Architecture defines the automated flow of informaton and control through the enterprise. It also defines flow of information to the Human component of the organization, and the return of commands to automated systems at all levels. The Control and Information System also includes "low level" automated control loops, and those higher level control functions which have been automated.

The control and information system architecture is the newest of the architectures, since automation of any kind was not possible before the industrial revolution. The "Jaquard Loom" was probably the first programmed discrete manufacturing production machine, and its automation, although revolutionary was very locallized. The first regulatory control loop was the centrifugal regulator invented to control steam pressure on locomotives. Although control loops in early refineries were many, most were given "set points" by an operator in a local "unit control room", so graphical representation could be limited to the PFD and P&ID. By this process, the P&ID evolved to define both the "low level" automation functions, and the physical production facility. In this the P&ID is unique, in that it also shows the interface between the low level control functions and the physical production facility.

P&IDs do not, however, represent the "higher level" Control and Information Systems functions or networks. Initially, this was not necessary, since the Human and Organizational component of the Enterprise was responsible for all of these functions. Most recently however, the advent of industrial LANs, Enterprise Integration, MRPII (Manufacturing Resource Planning), etc., has resulted in very complex "higher level" systems. These must be visualized in order to understand and analyze them.


by Gary Rathwell reserved

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