Data-oriented design: the library metaphor
The capabilities of the computer with respect to data storage and retrieval have led to an information system concept analogous to a library. The information system is seen as a large library in which information is stored in an orderly and systematic way. The use of the library consists of retrieving the information one needs in the form of books. This approach to information systems was as data-oriented design revolutionary in the 1980s (Martin, 1982; 1983). Processes are seen as operations on a database. The database is ordered according to object types and relationship types. In the database, stable states are distinguished. Transactions are the transitions of one stable state to another; program modules are based on transactions. Transactions can be thought as being composed of basic operations on attributes of object types; in object-oriented databases these basic operations are defined as methods. A special type of transaction is concerned with the derivation of attributes based on the values of other attributes; this derivation can be based on a special inference engine that uses inference rules.
The capabilities of the computer with respect to computation lead to efforts aiming at the design of the most efficient algorithms to perform a certain computational task. In the spirit of Taylor, one should redesign each computer task using the most efficient algorithms, thus specifying a method that minimizes the use of precious computer time. In this way, a library of algorithms or program modules can be formed that can be used to compose larger programs. The transactions and inference methods of the data-oriented design are examples of these larger programs.
Processing of data to get information
A mill processes water or other material. Data can be seen as raw material, while information is a product. An information system is often seen as an automaton that processes raw materials (data) in order to get products (information).
“An information system is a set of organized procedures that, when executed, provides information to support decision-making and control in the organization.” (Lucas, 1986: 10).
“Computers have become an essential part of organizational information processing because of the power of the technology and the volume of the data to be processed” (Davis and Olson, 1985: 4).
“Information is data that has been processed into a form that is meaningful to the recipient and is of real or perceived value in current or prospective action.” (Davis and Olson, 1985: 200).
Information can also be seen as water flowing through a channel (Davis and Olson, 1985: 202).
Coherence by design
In a case that coherence only can be brought about by a top-down design, integration of information systems at design time is important especially in a virtual office. Such an integration of information systems has the following objectives (Theeuwes, 1986: 96):
- tuning of the information systems to the business processes;
- integration of information systems and data collections;
- development of new information systems by projects based on strategic data planning;
10
- planning and management of the technical infrastructure necessary for the integrated information systems;
- design an organization for the development and maintenance of information systems and data collections.
The informational aspect system
The integration idea leads, in its most extreme form, to the concept of one information system for one organization (the total information system). A related idea is the integration of information systems from the viewpoint of the informational aspect system of the organization. This idea is related again to the idea of control by aspect systems: financial control, human resource control, material resource control, and so on. With respect to this control, a neat planning and control hierarchy based on Anthony’s (1965) theory is strived after. It is consistent with this concept to consider ‘the’ information system as an aspect system of the organization, comprising:
“- the organizational subsystem made up of people and procedures;
- technical appliances;
- programs
- data” (Boersma, 1989: 6).
The organization’s information system has to be managed as a whole by an information manager and a data administrator. This abstract information system is often subdivided in integrated aspect-oriented information systems for finance, marketing, personnel, materials management, and so on. Information is seen as a resource to be managed centrally. Data are processed by transaction processing systems and by management information systems that produce information necessary for office space decision-making. Standardization of financial procedures, intensifying financial control, integration of the components of the organization’s information system, and centralization of data administration are seen as important topics for information management. Because of the uniqueness of the organization’s information system, software has to be tailor-made.
The resulting planning and control design leads, however, to problems. It is an example of controlling organizational activity by planning and control organized by aspect systems. Kastelein’s (1985: 204) view on this type of control is:
“There is an unstoppable process of interweaving and stitching through of the organizational web in which the organizational units are embedded, resulting in the increasing restriction of substantial change possibilities, and the suffocating of already going change processes.”
Another result of thinking in terms of an informational aspect system is the resulting passivity of managers and users, who leave the design and building of information systems to the computer specialists.
Design of architectures and building activities
A central role in the design of integrated information systems is played by the architectures distinguished in the strategic data planning approach to information planning (Martin, 1983, 1984; IBM, 1984). To optimize an information system, the principle of minimizing information exchange between subsystems is used. This 11
principle is based on Simon’s (1962) ‘nearly decomposable system’ concept. Simon argues, that processes that are subdivided in hierarchically organized subprocesses are more efficient than non-subdivided processes. This is a result of the localization of the effects of external disturbances during execution.
After planning, determining requirements and design, the information system has to be built. This is traditionally accomplished through structured programming techniques (Lundeberg, Goldkuhl, and Nilsson, 1982; Jackson, 1983). In short, for designing and building information systems based on the mill metaphor, a well-developed toolkit exists.

_________________________________________

www.traditionalhealthways.com | www.sermonhifi.com | www.sermonhifi.com/blog | www.traditionalhealthways.com/blog