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Unit 1: Introduction to Information System Development
2. Processing requirements: What are decision rules, calculations are required to convert Notes
input into output. How much time it takes for processing the input into output?
3. Storage requirement: What is the size of data base, whether it is a common data base or
distributed. What are the queries of the user?
4. Control requirements: What are the types of measures of accuracy, validity, safety, security and
adaptability requirement for system input processing, output and storage function adopted.
1.1.4 Design
The previous stages depict what users demand from the system in order to fulfill their information
needs and aims at answering “What is needed?” System design stage gives answer to the question
“How” the system will accomplish the objective. Systems design consists of design activities
that produce system specifications, satisfying the functional requirements developed at the
analysis stage. System design consists of two steps – conceptual design and the a detailed design
of the information system.
Conceptual Design
Conceptual design represents the structure of Information System. The input to this stage is
information requirement and management objective and the output is the performance
requirement of those who will develop the detailed design.
The process of conceptual design involves showing the feasibility of meeting the management
objective for Information System. This is the phase of system development which gives answer
to the question “how” the system will work at gross or high level.
Figure 1.3 shows various activities at the time of design.
Figure 1.3: Key Activities at the time of Conceptual Design
Define the Problem in more detail
Refine the management objective to set system objective
Establishing system constraints
Determine information needs and sources
Document the system concept
Prepare the conceptual design report design
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