System implementations methods.
Method of implementation – method of conversion from an old system to a new one
Direct changeover
Involves the Old system being completely dropped and the new system being completed installed at the same time;
Need to make sure the new system is completely functional and operational;
This conversion method is only used when it is not feasible to operate separate systems at the same time;
Any data and training must be done before the installation.
Advantages |
Disadvantages |
New system available to everyone in the company immediately |
The riskiest method - if something goes wrong, there is nothing to fall back on. Have to wait while the problem is fixed. |
Often the cheapest method of installation |
Have to transfer all of the data to the new one before the old one can be switched off |
Don't need to keep duplicate sets of data |
There will be a period of time where no system is available because can't have the old one working while a new one is being switched on |
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There will be a period of upheaval while the system is brand new and staff are finding their way around it |
Parallel conversion
Involves the operating of both systems being run for a period of time;
This allows problems with the new system to be found without loss of data;
Once the new system is fully functional and operational the old system can stop being used;
A consequence of using this is that old versions must continue being supported until the conversion.
Advantages |
Disadvantages |
Less risky than the direct method. If the new system fails, the old system is still up-to-date |
Time-consuming as data has to be entered onto both systems |
Less stress for staff as they still have the security of the old system |
One system can become out of sync. with the other. |
Staff can take their time to learn to use the new system |
Maintaining duplicate sets of data can lead to errors |
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The extra cost of running and maintaining two systems |
Phased conversion
The phased method of installation from an old system to a new one through a gradual introduction of the new and discardation of the old;
This is usually done by introducing new parts of a system while removing/replacing old ones;
Often used when the product as a whole is still under development;
Over time the entire system will be converted from old to new.
Advantages |
Disadvantages |
Less risk of the whole system going wrong, if something happens, it will only affect that specific part. |
This method of installation can take a long period of time |
Staff are introduced to the changes in small stages |
As parts of the system are used, users ask for changes which then hold up the installation of the next phase |
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It might be difficult to integrate the old and the new systems |
Pilot conversion
The new system is installed for a small number of users;
Users learn, use and evaluate the new system;
Once the system is seen as satisfactory the new system is installed and used by all;
Allows users to become experts and teachers of the new system;
Pilot conversion also allows for testing the product in an operational setting.
Advantages |
Disadvantages |
Only a small part of the business is affected. The rest of the business continues using the old system for now |
Even though it is only introduced to a small number of departments, those chosen will have the same disadvantages experienced as for a 'direct changeover' |
Any problems or issues are identified without it affecting the whole company |
Those staff using the new system might not be able to easily share data with the rest of the company who are still on the old system |
When the rollout happens, staff from the pilot departments can be involved in training other staff |
Extra work for IT staff who are having to support two different systems |
Importance of system implementation plan
- Determine the timeline for implementation
- Determine the implementation method
- Determine the timing of staff training
- Determine the training method for personnel
- Provide proof of user agreement
- Provide proof showing that the client tested the software