2 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 )
3 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 easilythere are always some square pegs that simply wont fit in the round holes.
4 Data Conversion (cont.) 4 methods of data conversionsAdvantages & DisadvantagesCase:A school, purchased new scheduling and accounting system based on database system that incompatible with the existing system.
5 4 method of data conversion Direct Conversion ( plunge , direct cutover )Parallel Operation ApproachPilot Operation ApproachPhase-in Approach
7 Direct Conversion ( plunge , direct cutover ) Least desirable approachStop old system, and start new system on a given dateIn this approach the old system ceases and the new system commencesIt 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.
9 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.
11 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 cut-over 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.
13 Phase-in Approach (piecemeal approach) In this approach the new system is implemented 'module' by 'module'.-eg. Accounting packages are appropriate:-accounts receivable-accounts payable-inventory-sales-payrollThe 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 itCan also result in long conversion times.
14 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.
15 References:Shelly, Cashman & Rosenblatt, Systems Analysis and Design, 6th Edition, 8th Edition, Course Technology, 2006, 2010.