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Analysis & Design of Information Systems

Notes  Entities and their characteristics.
 The relationships these entities have with each other.
 The integrity rules, i.e., how data is maintained and used in the information system.
3. Process Design: It involves the design of process i.e., the design of software programs,
procedure needed by information system. At this stage the developer has to decide about
the detailed specification of software, that is either software has to be purchased, or
developed or it is purchased and modified according to the proposed system requirements.
The product of this stage is to know system specifications means, the details of a proposed
system. So the system analysts along with management and information system user can
use their expertise to design a new or improved Information System.
Finally, system design should be such, which specifies what types of hardware, software,
data, people and network resources are required to make a better Information System. It
also specifies how such resources will convert data resources into final information product
which is needed or expected by the end user from the Information System.

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Caution Before implementation and after designing the proposed system, the system must
be tested because this is also one of the major activities of a detailed design.
There are three ways to get system feedback on the viability of designed Information System:
(a) Modeling

(b) Simulation
(c) Test planning.
The importance of testing at the designing stage is much because any fault or problem discovered
at this stage will be easily removable, less costly and will reduce overall project cost.

Task Make distinction between data design and process design.

1.1.5 Cross Life-cycle Activities

Till now we have discussed the basic stages of Information System life cycle development
approach. Actually information system development also involves a number of cross life cycle
activities means, any activity that overlaps many or all stages of the information system
development process.

Example: Documentation, presentation, feasibility analysis, fact finding, project and
process management.

Fact finding activity relates to collect information by means of interview, personal observations,
questionnaire and other technique regarding the problems, opportunities, requirements and
their priorities. This activity can be required at many stages during the completion of the whole
information system development process. At an early stage, i.e., investigation stage, it is related
to learn about a business’s problem, opportunities, requirements, constraints, objectives and
their priorities. Fact finding is also required for design analysis, detailed decision final design
implementation and maintenance stages.

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