CORPORATE INFORMATION-SYSTEMS AND INFORMATION TECHNOLOGIES

A corporate activities model is introduced. This is a business-cycle model composed of PLAN, DO, and SEE activities and the information flows connecting them. This model is constructed on two layers; an organizational layer and an individual layer. According to the corporate activities model, corporate information systems are classified into PLAN, DO, and SEE information systems at an organizational layer, and PLAN and SEE information systems at an individual layer under organizational DO activities. Next, regularity of both data structures and algorithms is defined from program production aspects as follows: if the data structures and algorithms of a program can be defined prior to all computations, they are regular, otherwise they are irregular. The above classification of information systems can also be clearly explained in terms of regularity. It is also shown that unique information technologies are required to develop each system. Finally, several information technologies are proposed for each information system: real-time database maintenance for DO information systems, a data supply system for SEE information systems, an automatic index generator and a virtual office environment for PLAN information systems, and private data management and automatic terminal operation for PLAN and SEE information systems at an individual layer under organizational DO activities.