Page 13 - DCAP205_DCAP409_ANALYSIS_AND_DESIGN_OF_INFORMATION_SYSTEMS

Unit 1: Introduction to Information System Development

Develop alternative conceptual designs and select one: Every problem can be solved in a number Notes
of ways. So before selecting the most feasible alternative, one has to evaluate each alternative in
the light of:
1. Compare anticipated performance of the conceptual design with the objectives of the
system.

2. Prepare a rough or preliminary cost-effectiveness analysis of the information system.
3. Examine the flow chart for strength and weakness of each conceptual design.
4. Expand the conceptual design in more details, if none of these provides a preferred design.
Document the System Concept: In this stage manager participation to the design process shows
what input, output, master files and rules for processing are required. The general system flow
chart is a common method of indicating the general structure of a computer based information
system. System flow also reflects the design efforts before and after this stage. At this stage the
formats of input are designed. The input received from outside sources is then converted into
machine usable forms. The output data definition includes the specifications of the destination
like where they go and in what form, etc. Including the specification in what percentage one gets
the output and at what frequency and form it will take, i.e., hard copy, soft copy, etc. After
preparing the output and after input has been documented, the last step is to prepare a report for
the manager.
Prepare the Conceptual Design Report: The conceptual design report, is in a sense a proposal for
the expenditure of funds and for organizational change. In nutshell, it consists of performance
specification, function to be performed by the system and means by which each function is
measured. Along with this report separate documentation should be provided.
Detailed Design

In order to make a detailed design, first of all the system designers have to gain the support of
all the staff members from top to bottom level. To seek their acceptance it is better to involve
them in the designing process.
The designer uses four sources for the design of the Information System. They are task force
meeting; for a larger system an interview with the top, intermediate level manager and a
selected group of operating staff; study the internal and external source document; and at last
personal observation of operations and communications.

The detailed design is done for the areas of designing user interface, data design and process
design.
1. User Interface Design: The user interface design activity is related to facilitate the interaction
between the user and their computer based application. This involves:
 On which operating system the Management Information System should be based.

 Concentrate on the design of attractive and efficient forms of user input and output.
 Design methods of converting source document into object document means
converting human understandable form to machine understandable language.
This activity produces the detailed design specifications for information product like
display screen, forms, documents and reports.
2. Data design:

 It includes the design of the structure of databases i.e. what type of specific data
element is carried.

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