Objectives: Introduction Over View of System Analysis and Design
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- Figure 2.2 Steps in systems design
- Test programs
| 2.2.5 Implementation The implementation phase is less creative than system design. It is primarily concerned with user training site preparation, and file conversion. When the candidate system is linked to terminals or remote sites, the telecommunication network and tests of the network along with the system are also included under implementation. During the final testing, user acceptance is tested, followed by user training. Depending on the nature of the system, extensive user training maybe required. Conversion usually takes place at about the same time the user is being trained or later. In the extreme, the programmer is falsely viewed as someone who ought to be isolated from other aspects of system development. Programming is itself design work, however. The initial parameters of the candidate system should be modified as a result of programming efforts. Programming provides a “ reality test for the assumptions made by the analyst. It is therefore a mistake to exclude programmers from the initial system design. Figure 2.2 Steps in systems design Outpu t Design Input Design File Design Processing Design Detailed System documentation Design submit for approval Design accepted Test programs Implementatio n phase System testing checks the readiness and accuracy of the system to access, update and retrieve data from new files. Once the programs become available, test data are read into the computer and processed against the files) provided for testing. If successful, the programs) is then run with “ live data. Otherwise, a diagnostic procedure is used to locate and correct errors in the program. Inmost conversions, parallel run is conducted where the new system runs simultaneously with the old system. This method, though costly, provides added assurance against errors in the candidate system and also gives the user staff an opportunity to gain experience through operation. In some cases, however, parallel processing in not practical. For example, it is not plausible to run parallel two online point-of-sale (POS) systems fora retail chain. In any case, after the candidate system proves itself, the old system is phased out. Download 0.94 Mb. Share with your friends:
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