The managerial structures and social processes of the organization are not normally treated as part of its information technology. However, in order to be successful the technical systems must be consistent with the organizational structures and processes. This applies particularly to inter-personal communications where computer networks will not be used if they violate the managerial and social norms of the organization, and to command and control paths which have to conform to existing authority and procedures that are not necessarily those of the organization chart.
The technical problems are beginning to be resolved at the lower levels by the adoption of industry standards in communication protocols such as the open systems interconnection (OSI) standard, the provision in data-processing and database packages for the import and export of data from "foreign" systems, and the provision of data-communications for parameter-setting and data-collection in control and instrumentation systems. These alone are necessary but not sufficient to allow the widespread creation of integrated systems. They provide a syntactic framework for system integration but no coherent semantics in which to express it.
Remote Communications are necessary to interface the organization with the organizational world in which it operations A particular organization is part of an infrastructure each part of which is trying to optimize its own operations.
Computation Systems perform the classical number-crunching tasks under the control of algorithms that with modern software engineering have a high degree of accuracy, conformity to specification and reliability.
Database Systems have become the classic core of an organization's information system, recording all its activities in a co-ordinated fashion and making the information available on a controlled basis to those systems and people with a legitimate need to know.
Control Systems are now increasingly integrated with information systems so that decisions can be implemented directly in the physical world.
Instrumentation Systems are also increasingly integrated to provide timely information on the state of the physical world and the effectiveness of operations.
Knowledge Bases are distinguished from databases by containing inference rules rather than facts. The rules may necessarily be heuristic in nature, generating plausible advice rather than hard facts. If databases may be said to record an organization's activities then knowledge bases may be said to record its skills.
Expert Systems are the means to apply a knowledge base to the solution of a particular problem. They stand in relation to the knowledge base as does conventional computation to the data base. They differ in that their role as advisors and dependence on heuristics makes accountability and comprehensibility of major importance. An expert system has to be able to justify and explain the basis of its advice.
Simulation has been separated from other forms of computation because it is computation based on a model of some other system and it is the relation of the simulated model results to that of the system modeled that is of paramount importance. The models used in simulation to infer the behavior of a system are generally deeper than the models used in expert systems to infer the proper advice about a system, even though both may be concerned with the same system.
The first level defines standards for the physical transfer of messages--electrical levels, timings, connectors, and so on.
The seventh level defines standards for the content of messages in relation to applications programs.
Intermediate levels are concerned with intra-message validity, network addresses, end-to-end message transfer checking, correct sequencing, and standard data formats for very general data structures such as graphics.
The most important concept underlying the OSI model is that of virtual circuits. Designers of a particular level are concerned primarily with its relation with the equivalent level in the system with which it is communicating. They need have little concern with the levels above or below it. Hence they think in terms of messages passing directly between equivalent levels, through a "virtual circuit," rather than through the multiple levels of the actual system.
The top level above the OSI defined layers is the "user level virtual circuit," representing the interactions between user programs through the communications network, and hence the interactions between users themselves, and their activities, if the programs are interactive. This concept of virtual circuits between users, and user activities, is very powerful in enabling the first figure to be restructured to provide a more integrated framework for the other sections not directly included in the communications protocol. It can be redrawn in such a way that the relation of managerial and operations considerations to higher-level protocols in integrated communications networks is apparent.
The next figure shows the same conceptual blocks as those in the first figure, but now in hierarchical form with the person-computer interface, information systems, organizational structure and external worlds shown as higher level "layers" above the network layer. In OSI terms these upper layers may be seen as subsuming and extending the presentation and application layers of the protocol, and give substance to the user level virtual circuit.
The virtual circuits between the human-computer interface layer and the information systems layer are easy to understand. The user of a computer terminal does not think of himself as communicating through a network but rather as directly interacting with some data-processing sub-system. This layer may go beyond the OSI specification but it seems a natural extension of it to the technical aspects of the interaction between people and computing systems. However, the "virtual circuits" at the level above, between the organizational layer, and the external world layer, may seem rather less credible. It is a reasonable metaphor that the sales manager does not see himself as interacting with a complex administrative and productive system, but rather as communicating directly with a customer organization by supplying it with goods. It is a reasonable metaphor that the chief executive does not see himself as concerned with that level of communication but rather as communicating directly with the board and shareholders through a flow of profits and dividends. However, can these metaphors be given technical substance through extension of the layered hierarchical model of virtual communication paths?
The main problem in extending the model to the management level is that people are directly and necessarily involved, and they have different dynamics from technical systems. However, this is also true for the level below where human-computer interaction is involved, and models have been developed at this level that integrate the human and technical components with a hierarchical layered communication model.
go on as before with stand-alone equipment
buy from one supplier
develop standards approach to communications problem
In order to achieve (e.g. 1 above) I . . . .