Week 9

This post gives the different approaches of chageover methods to answer th week 9 question.

System Changeover: System changeover is a process of retiring the old system and installing the new information system.There are four different types of changeover methods depending on how they are inmplemented.They are discussed  breifly as follows.

Direct Cutover: The direct cutover approach causes the changeover from the legacy system to the new information system immediately when the latter one becomes operational. Direct cutover is the least expensive one when compared to all other changeover methods because the IT group has to work and maintain only one system.Direct cutover has more risk than other methods. Despite of thorough and careful testing and training, some difficulties can arise when the system is operated lively. A system also can face more difficulties at thhe real time than in the testing phase.Companies often choose the direct cutover for implementing commercial packages. Direct cutover is also used in arganisation where old and new system both cannot be supported alternatively.

Parallel Operation: In this method both old and new systenm are executed fully for a specific period of time.Data is inputted in to both the systems and the feedback generated are compared for the accuracy.When the IT group satisfies that new system is performing correctly then the old system is terminated.The main advantage of paralell appraoch is low risk.If the new system does not work properly then the organization still performs its operations with the old system.Errors in new system can also be spotted easily with paralell operation method.This technique however has disadvantages since it is very expensive because the company has to pay for both operations.New employees should be hired to maintain the workload.

Pilot Operation: The pilot operation is a technique where a selected location of a company is changed with the new system. That location is termed as pilot site. During the pilot operation the rest of the organization will be running the old system.When the experts think that the system in the pilot state is working correctly then the whole system is changed using direct cutover method.So pilot operation is a combination of parallel operation and direct cutover methods.

Phased Operation: The phased operation method allows to implement the new system in stage wise.And each particular stage is implemented by any of the other three changeover methods.This method is used to reduce the risk and cost.The errors are also limited to only implemented stage.The employees are also comfortable with this method because a more dlear understanding is possible.