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 informaEon from one system to another or one applicaEon to another. •  fundamental differences in systems designed by different manufacturers. •  informaEon 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 accounEng system based on database system that incompaEble with the exisEng system. 4 method of data conversion •
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Direct Conversion ( plunge , direct cutover ) Parallel OperaEon Approach Pilot OperaEon 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 opEons, but it is the most risky. •  Once in operaEon, 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 organisaEon could suffer significant financial loss. •  The direct cutover approach is normally used for the implementaEon of a purchased or standard system, where the chances of failure are low. Parallel OperaEon Approach Parallel OperaEon Approach •  In this approach both the old and new systems run together for a period of Eme. •  It is only when any problems with the new system are idenEfied and corrected that the old system is reEred. •  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 operaEon changeover strategy would be recommended if we cannot afford to except any risk. •  Best method for converEng a manual to a computer system. Pilot OperaEon Approach Pilot OperaEon Approach •  In this approach the new system is implemented in only one part of an organisaEon (i.e. in a pilot/test site). •  The old system conEnues to operate in the other parts of the organisaEon. •  Any problems with the new system are idenEfied and corrected at the pilot/test. •  Once this has occurs the new system can be implemented across the whole organisaEon, probably using a direct cut-­‐
over approach. •  Pilot operaEon becomes an opEon when a new system is to be implemented in a series of sites or departments. •  Can result in long conversion Emes. Phase-­‐in Approach (piecemeal approach) Phase-­‐in Approach (piecemeal approach) •
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In this approach the new system is implemented 'module' by 'module'. -­‐eg. AccounEng packages are appropriate: -­‐accounts receivable -­‐accounts payable -­‐inventory -­‐sales -­‐payroll The whole organisaEon 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 opEon 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 operaEon. Users become familiar with the new system liZle-­‐by-­‐liZle before having to fully rely on it Can also result in long conversion Emes. Case: A school, purchased new scheduling and accounEng system based on database system that incompaEble with the exisEng system. Choose a method that does not impact the students in any negaEve manner. •  From the above discussion about all four possible approaches, it is very clear that data cutover and parallel operaEon approach alone is not suitable. Due to the drawbacks like high risk or high cost but the combinaEon of both approaches namely pilot operaEon and phased operaEon approaches is more frui\ul. •  SEll phased operaEon is not most suitable approach as we know there are lot of phases involve in the informaEon system and also very costly. So conclusion is pilot opera*on is the most recommended approach for the school because this method is cheaper and safer method. References: •  Shelly, Cashman & RosenblaZ, Systems Analysis and Design, 6th Edi*on, 8th EdiEon, Course Technology, 2006, 2010. •  hZp://149.144.20.200/subjects/IS/sem22010/
lectures/l111implementaEon.html •  hZp://en.wikipedia.org/wiki/Parallel_adopEon •  hZp://www.scribd.com/doc/396849/Developing-­‐
BusinessIT-­‐SoluEons