On Roles of Models in Information Systems - Intentional Perspectives on Information Systems Engineering - page 19

2.1 Information Systems and Domain Systems
The distinction between the information system and the domain system may change
over time, and may differ among people who are involved in different parts of the
interplay between the information system and its domain. So parts of the informa-
tion system may sometimes by some be seen as being parts of its domain, and vice
versa. Also the borderline between the total system and its environment may at times
seem fuzzy. In practice it is sufficient that in the various situations it is made clear
whether a particular system component is part of the information system, its domain
or of the domain's environment.
Modeling the domain is an essential part of requirements elicitation in informa-
tion systems engineering. Initially the large volume of computer applications were
in the support of information processing in organizations, e.g., banking, finance,
government, retail, industry. Those were the applications where the large volumes
of data were found, and where data base technology found the largest markets.
Conceptual modeling was initiated from these application types. Depending on the
nature of the particular application domain these modeling efforts are called by dif-
ferent names, e.g., enterprise modeling [ 9] , business modeling [ 13] , agent modeling
[ 7, 15] , intention oriented information systems modeling [27 -29] .
The wide penetration of computers into most aspects of human activity has led to
a need for relating information systems engineering to every domain where comput-
ers are applied. Information systems engineering “in the domain” usually goes far
beyond the design of the information supporting role of the information system. The
ambition is usually to re-engineer the domain in order to take maximal advantage of
available technology, e.g., “business process re-engineering”.
In order to re-engineer in a particular domain it becomes necessary to relate
general IT-knowledge to the discipline knowledge of the relevant domain. So
the conceptual modeling theory of information systems engineering and software
engineering has to relate to all kinds of domain theories.
2.2 Information Systems and Data Systems
The distinction between digital and non-digital representation is not always used
as a criterion for decomposing information systems into structures of smaller parts.
Many information system components therefore is seen to consist both of com-
puterized parts and of parts where information is stored in non-digital forms, e.g.,
paper, and where the information processing is not done by computers but, e.g., by
people. In the computerized parts of an information system the information collec-
tions and messages must be encoded in some formal expression. The non-digitized
information may very well be informal, e.g., expressed in natural language. The
formalization of informally expressed information usually requires new details and
complexity to be added to the informal form. The interplay between formality and
informality often creates difficulties for the information exchange.