After acquiring a computer program (system) you are require to change from the old system to the newly acquired system in a process called system changeover. It involves replacing the old system and business processes with new once.
General activities carried out during changeover
Replace old hardware systems with new.
The new system may not be supported by the old hardware system; hence you will be required to replace them with new, i.e. the new system may require a high speed to process information. This means that you will require a server that has a bigger RAM and processing speed. Again you may require more storage space.
Replacing business procedures
New system may mean that you change the procedures that you use to carry out a certain process. If for example in old system you use to scan customer image before using the system and then now the new system require to use a webcam to capture image the it means procedure has to change.
System and other relevant administrators should be trained on how system should be managed because they will be tasked with maintaining the system. Another group to be trained is the end user who will be using system for data capturing and entry. Training should be done to give the user confident required when serving customer.
Conversion of data to suit the new system
If the old and new systems are using different data types then you will be required to convert the data from old format to new once. If the old system was a manual system then you digitalized data to be used in computerized system that you want to implement.
System Changeover strategies
It involves running both the new and old system concurrently until you are confident that the new system is working effectively with low risk. The strategy assures a rollback to old system in-case something goes wrong with the new system. The strategy also allows user time to familiarize with new system and gain confidence to use it.
The main shortcoming of this strategy is that it over strains resources because they are required in both systems. It requires large storage capacity to accommodate both systems. User will be required to do double entry of data, both in the old and new systems. It is also difficult to compare the two systems and how they output data because they may be completely different. Another problem comes in determining for how long you should run the old system before replacing it completely.
In direct changeover the old system is replace on time with a new system. It is mostly used when the risk of losing data from the old system is significantly low or if the system has most the functions that are new. It uses less resource because only one system is running.
With this system if something happens with the new system then it means no going back to the old system because it is no more. Users are not confident enough to use system on initial day of system implementation hence they operate relatively slow on the operation involved.
It means choosing a specific location or branch of the organization and implementing the system in that branch first. The branch (location) where the system is first test before it is implemented in the whole organization is called pilot site. It allow to test the system on a small scale on all it functionality and make any changes necessary to avoid any problems when later it is rolled on all organization branches.
The strategy is used as alternative to parallel change over because it cost less and it almost achieves the same results.
Phased involves implementing a module of the system at a time until the whole system is implemented. It combines the parallel and direct change over strategies. The module can be a functional part of the system or a specific subsystem. Each sub system is implemented until it succeeds that when the next one is implemented. It means in case the new system fail then it is only that part that is affected and not the whole system.
The main challenge is that before the whole system is implemented it may take long time.
Different strategies are used at different time depending with the organization circumstances at that particular time.