INFORMATION SYSTEM ARCHITECTURE DESIGN
Phase SD.1 General requirements analysis
be informed of the existing system
The study of the existing system must always be limited
to the essential. It may not become an extended
description of all the details of the current system.
Nevertheless, it is mandatory that the requirements
analysis is built upon a sufficient knowledge of the
existing system.
structure the scope of the study into
functional domains
describe the main flows between domains.
identify the main constraints
quantify the volumes to be
processed
identify the requirements
identify the main information requirements (satisfied
& not satisfied)
identify the functions & purposes by domain
set the priorities.
give a first diagnostic
also in terms of performances and cost of the current
system
propose new evolution
possibilities.
management choices
organization choices
technological choices: IT, telecom, ...
Interviews & workshops
Study of the existing system
Enquiry (organization chart, workforce,
available resources, main functions of the services,
documents inventory, documents flow)
Study of the existing documentation:
regulation
reports of the direction committee & reports of the
IT committee, previous architecture designs, audit
reports, ...
analysis documents, user documentation, applications
mapping.
General description of the current
information system
describe the main processes and their functions.
Note: When a part of the documentation lacks, it is
sometimes necessary to do a more detailed analysis of
the existing system. A this stage, the analysis will
anyway always stay focused to the identification of the
requirements (satisfied requirements by the way).
Estimate the results of the current
systems :
information system performances
realizations, volumes, delays, working and maintenance
costs, resources, performances.
Study of
the new requirements, that may raise from the evolution
of the domain or of its environment.
economical, marketing and customer
requirements
regulation
taxes
organization
users basic requirements
qualification, responsibilities, working hours,
friendliness, ...
technology
Identify the main constraints
Write a first diagnostic
Propose an action plan for the next
phase
Control by a second reading, simple or
alternate.
Key factors:
identify and take all needed information sources into
account
brainstorm efficiently to imagine the future evolution
At the end of this phase, you should:
select the requirements that need being
satisfied; rank them by priority.
agree on a limited number of
"acceptable" orientations .
agree on the methodology for the next
phase.
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