The process
followed in making a determination is called Feasibility
Study. This type of study clearly specifies that, the project should be taken up or
not.
Different
types of feasibilities are
1.���� Technical
is the most difficult to determine.
2.���� Economical
3.���� Operational
4.���� Time
5.���� Legal
6.���� Social
7.���� Management
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Feasibility
Study has to follow 8 steps, they are
1.���� Form
a project team & appoint a PL
2.���� Prepare
system flowcharts
3.���� Enumerate
potential proposed systems
4.���� Define
& identify characteristics of proposed system
5.���� Determine
& evaluate performance� & cost
effectiveness of each proposed system
6.���� Weight
system performance & cost data
7.���� Select
the best proposed system
8.���� Prepare
& report final project directive to management.
�
System
analysis is the fact finding followed by analysis of the facts. Data analysis is also
considered a pre-requisite condition for cost/benefit analysis.
While
considering the design alternatives, one should keep following points in mind to choose a
better alternative.
1.���� Greater
speed of processing
2.���� Effective
procedure to eliminate errors
3.���� Better
accuracy
4.���� Faster
retrieval of data
5.���� Integration
of data
6.���� Larger
capacity of storing data with reduced cost
7.���� Data
Security.
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Cost benefit
analysis will give a picture of how much cost will be incurred by the project. There are
four benefits of projects about cost,
1.���� Cost
Saving:� This lead to reductions in
administrative & operational costs.
2.���� Cost
avoidance: These are those which eliminate future in administrative & operational
costs
3.���� Improved
Service: Are those where performance of the system is improved by a new computer based
software system
4.���� Improved
Information: Is where computer based methods lead to better information for decision
making.
�
Cost
benefits are classified as
1.���� Tangible
or intangible
2.���� Fixed
or variable
3.���� Direct
or indirect.
�
Cost benefit
can be summarize as
1.���� Method
by which we estimate the value of the gross benefits of a new system specification.
2.���� Method
by which we find & determine the increased operating costs associated with the above
mentioned gross benefits.
3.���� The
subtraction of these operating costs from the associated gross benefits to arrive at net
benefits.
4.���� Method
by which we find & estimate the monetary value of the development costs that produce
the above mentioned benefits.
5.���� Methods
by which we show the time phased relationship between different costs.
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Learning as
much as from the existing system is called Fact-finding Different methods of Fact findings
are
1.���� Interviews
Personnel
2.���� Questionnaires,
can have multi choice, rating, open ended & Ranking questions.
3.���� Observing
current system
4.���� Going
thru the current forms & documents
5.���� Find
the data flow in the existing system
6.���� Define
the system requirements
�
After
finding the data, analyst prepares a Data Flow Diagram (DFD) which depicts
the flow of data in different elements of the system. Which gives us a graphical Overview
representation.� To draw a analysis DFD,
1.���� Look
at the system from the inside to the outside
2.���� Identify
the activities
3.���� Locate
the data flows
4.���� Show
the relationship between activities
5.���� Find
the internal� i/p or o/p that exist within the
system
6.���� Level
complex process in the DFD into simpler ones
7.���� Look
for duplication of data flows or data stores.
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Data
Dictionaries defines each term (called a data element) encountered during the analysis
& design of the new system. Data elements can describe files, data flows or processes.
It helps analyst to define precisely what they mean by a particular file, data flow or
process. Data dictionary uses few major symbols, they are
=��������� Equivalent
to
+��������� AND
[ ]������� either/or
( )�������� optional entry.
There are
four rules to be followed while constructing a Data Dictionary.
1.���� Words
should be defined to stand for what they mean & not the variable names by which they
may be described in the program.
2.���� Each
word must be Unique.
3.���� Aliases
or synonyms are allowed when two or more elements show the same meaning.
4.���� Self-defining
words should not be decomposed.
�
After
following the these rules, define variables with there data types and their properties
like unique or increments automatically.
There are
two types of Data Dictionaries
1.���� Integrated:
is a related to one DBMS
2.���� Stand
Alone: is not tied to any DBMS, although it may have advantages of DBMS.
�
Both types
of DD can be identified by functions as Passive,
Active or in-line.
The
functionally passive DD performs only Documentation.
The Active
DD supports program and operations development by exporting database definitions for
languages like COBOL & JCL for execution time performance.
An in-line
DD is active during program execution, performing such feats as transaction validation
& editing. |
