Information Technology Reference
In-Depth Information
methodology is the splitting of the system into smaller parts, in order to establish
the order and the interaction between the different stages, and the usage of modeling
methods and diagrams to present a more structured and logical de
nition to users
and developers (Manteghi and Jahromi
2012
). With this structured and analytical
system, it is possible to decompose the system into small units, with the purpose of
de
ning the meaning, order, and connections between the various units that com-
pose a large-scale information system.
A typical SSAD method will be divided into a maximum of 8 stages. The
first is
strategic planning, where an analysis of the current environment is undertaken,
along with a discussion and establishment of the plan and scope of the project. This
is followed by a feasibility study that aims at determining if the project is techni-
cally,
financially and socially viable, as well as how it
fits within the organization
'
s
culture and goals. Next, there is a thorough analysis and speci
cation of require-
ments, where current systems and respective problems are evaluated, and what is
necessary for a new system to address existing issues and necessities. This infor-
mation is collected by a variety of methods, including surveys and observation as
well as resorting to existing studies. The next stage is logical system speci
cation,
where according to the requirements found in the previous stage, a set of technical
solutions is established. At this point, the planned system is more speci
c and to-
the-point. Thus, it is followed by physical design, where the logical system is given
from through program specifications, database definitions, etc. The next stage is
construction and testing, when the actual programming and assembly takes place.
Transition entails the process of moving from an old system to the newly built
system. Finally, the last stage involves production, maintenance, and review. The
new system is established, and after its implementation, its success and adequacy is
measured for further studies and alterations (Goodland and Riha
1999
).
The SSADM deals primarily with three data-oriented views, namely logical data
structures (LDS), data
flow diagrams, and entity life histories (ELHs) that dem-
onstrate how organizations change over time (Avison and Taylor
1997
). However,
a closer look at the related literature reveals that there are ten speci
c SSADM
techniques. These are (Edwards et al.
1989
) as follows:
Data
flow diagrams (DFDs)
Logical data structures (LDS)
Entity life histories (ELHs)
Relational data analysis/third normal form (RDA/TNF)
Composite logical data design (CLDD)
Process outlines (POs)
Logical dialogue outlines (LDOs)
First cut data design (DD)
First cut programs (PROG)
Physical design control (PDC)
Besides the techniques listed above, Ashworth (
1988
) presents several basic
principles regarding this methodology (see Table
3.1
).
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