Data Conversion
Khoo Kay Vin
Data Conversion
• Convert Computer data from one format to
another.
Example:
• Words ( .docx to .pdf )
• Image ( .jpeg to .png )
• Audio ( .mp3 to .AAC )
• Video ( .avi to .mpeg4 )
Data Conversion (cont.)
• move information from one system to another
or one application to another.
• fundamental differences in systems designed
by different manufacturers.
• information like names addresses and phone
numbers transfer fairly easily
• there are always some square pegs that
simply wont fit in the round holes.
Data Conversion (cont.)
• 4 methods of data conversions
• Advantages & Disadvantages
Case:
• A school, purchased new scheduling and
accounting system based on database system
that incompatible with the existing system.
4 method of data conversion
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Direct Conversion ( plunge , direct cutover )
Parallel Operation Approach
Pilot Operation Approach
Phase-in Approach
Direct Conversion
( plunge , direct cutover )
Direct Conversion
( plunge , direct cutover )
• Least desirable approach
• Stop old system, and start new system on a given date
• In this approach the old system ceases and the new system
commences
• It is the cheapest of the four options, but it is the most risky.
• Once in operation, do not have the old system to fall back on.
What happens if the new system has problems?
• There is no back-up and data could be lost.
• In an extreme case the organisation could suffer significant financial
loss.
• The direct cutover approach is normally used for the
implementation of a purchased or standard system, where the
chances of failure are low.
Parallel Operation Approach
Parallel Operation Approach
• In this approach both the old and new systems run
together for a period of time.
• It is only when any problems with the new system are
identified and corrected that the old system is retired.
• This is an expensive approach as everything is duplicated.
• Can result in user resentment as there is an extra workload.
• However, risk is minimised and a parallel operation
changeover strategy would be recommended if we cannot
afford to except any risk.
• Best method for converting a manual to a computer
system.
Pilot Operation Approach
Pilot Operation Approach
• In this approach the new system is implemented in only
one part of an organisation (i.e. in a pilot/test site).
• The old system continues to operate in the other parts of
the organisation.
• Any problems with the new system are identified and
corrected at the pilot/test.
• Once this has occurs the new system can be implemented
across the whole organisation, probably using a direct cutover approach.
• Pilot operation becomes an option when a new system is to
be implemented in a series of sites or departments.
• Can result in long conversion times.
Phase-in Approach
(piecemeal approach)
Phase-in Approach
(piecemeal approach)
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•
•
•
•
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•
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In this approach the new system is implemented 'module' by 'module'.
-eg. Accounting packages are appropriate:
-accounts receivable
-accounts payable
-inventory
-sales
-payroll
The whole organisation receives parts of the system in stages.
The risk of failure is restricted to only part of the system being implemented.
This approach is incremental and is less costly than parallel changeover.
It is an option when a system can be broken up into self contained modules.
The changeover of each module could be carried out by direct cut-over or by
parallel operation.
Users become familiar with the new system little-by-little before having to fully
rely on it
Can also result in long conversion times.
Case: A school, purchased new scheduling and accounting system based on database
system that incompatible with the existing system.
Choose a method that does not impact the students in any negative manner.
• From the above discussion about all four possible
approaches, it is very clear that data cutover and
parallel operation approach alone is not suitable. Due
to the drawbacks like high risk or high cost but the
combination of both approaches namely pilot
operation and phased operation approaches is more
fruitful.
• Still phased operation is not most suitable approach as
we know there are lot of phases involve in the
information system and also very costly. So conclusion
is pilot operation is the most recommended approach
for the school because this method is cheaper and
safer method.
References:
• Shelly, Cashman & Rosenblatt, Systems Analysis and
Design, 6th Edition, 8th Edition, Course Technology,
2006, 2010.
• http://149.144.20.200/subjects/IS/sem22010/lectures/
l111implementation.html
• http://en.wikipedia.org/wiki/Parallel_adoption
• http://www.scribd.com/doc/396849/DevelopingBusinessIT-Solutions