week-9
An explanation of the four possible approaches discussed on page 447 of the course text book for changing from one information system to another. Explaining the implications and the benefits of utilizes these four approaches at CQU on the Capricornia Car Pool System.
Direct Cutover
The direct cutover approach causes the changeover from the old system to the new system to occur immediately when the new system becomes operational. (Text book, p448) For CQU this approach is cost effective and is the least expensive changeover out of all four approaches. However this approach involves the most risk and for the CQU CCPS may encounter errors that were not foreseen in the testing of this new system. Implementation problems are at a higher level using this approach, also detecting mirror problems are difficult because there is the inability to compare to a legacy system. Major issues can result in loss of customers as there is no backup of the legacy system. The CQU must decide if this system is non-critical and if the direct cutover is the only option. Timing is an important factor that will need to be considered as customer information may be lost creating errors. CQU would benefit from this approach as the old system is a manual diary system and the CCPS is the first technology based system for its department.
Parallel Operation
The parallel operation changeover method requires that both the old and the new information systems to operate fully for a specified period of time. (Text book, p448)
Data input and printing outputs are run on both systems and comparisons are made until the company are content with the new system. For the CQU is approach is the lowest risk of all the approaches, if the new system have problems the CQU can go back to using the old system as a backup. If changes are needed to be made to the new system customers and information will not be lost. However parallel operation is the most costly approach as both systems are running together and additional workloads are created when data needs to be entered twice. Parallel operation approaches are not appropriate when the two systems perform different functions and involve a new method of business operations i.e. the CQU CCPS legacy system is a manual operated diary.
Pilot Operation
The pilot operation changeover method involves implementing a complete new system at a selected location of the company. (Text book, p449) During the pilot operation the old system continuous to operate for the company, once the system has proved to be successful it is implemented fully. This approach is a combination of the direct cutover and parallel operation. The difference of implementing this approach is this method is cost effective than the parallel operations approach, and there is less risk allowed than the direct cutover method. For CQU this method would be hard to implement as the CCPS only operates in the one office, but it may be useful if at a later date the CCPS were to be implemented at other campuses.
Phased Operation
The phased operation changeover method allows you to implement the new system in stages, or modules. (Text book, p449) This method is another approach with the combination of the direct cutover and parallel operation. However with a phased operation you give part of the system to all users. An advantage to the phased operation is it is less risk of errors or failures, and it is less expensive than full parallel operation because you only work on a small part of the system. The disadvantage of this type of approach is it is not likely to be able to be used on a system that cannot be separated easily into modules. For CQU this method would be hard to implement as the CCPS is a new system to a manual system it would be difficult to decide what modules to use and not use as the CCPS is only a small system.
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