Information Technology Reference
In-Depth Information
2.4.2.
Generic diagram of information flow
RAMSES structures knowledge of the design on the basis of a generic diagram
representing information flow in an IIS; see Figure 2.3 [MOU 07]. The definition of
this diagram implies the specification of the entities involved and their relations, the
formalization of use activity of the system by users and the description of the
different contexts of use. Indeed, the objective of the design of an information
system is to support, assist and/or extend the activity of a user by making relevant
information available in its context of use.
The information flows exchanged between the user and the IIS are also
illustrated in Figure 2.3. Typically, an information need of a user is transmitted to
the IIS via the intermediary of an interface or a medium. The elaboration of a
response adapted to this need by the IIS is based on the adequate and available data
resources. The system then transmits the information to the user via the adapted
interface and medium.
Figure 2.3.
Diagram of information flow in an IIS
This generic diagram sets the entities to be defined to model the functioning of
an IIS. To build this model, the designers must have a methodology that structures
both analysis of the problem and construction of the solution. The classic
information system design methods propose management of the development cycles
that structure the project into phases of analysis, design, realization and validation. It
is nonetheless necessary to add an additional approach enabling the generation and
transmission of data coming from the analysis of reality (problem, need,
specifications) to the design of the system (models, architecture). In other words, it
is mandatory to propose a method that enables us to first of all find what the model
will need to represent [CAV 00].
