Parallel running
Parallel running is a strategy for system changeover where a new system slowly assumes the roles of the older system while both systems operate simultaneously. This conversion takes place as the technology of the old system is outdated so a new system is needed to be installed to replace the old one. After a period of time, when the system is proved to be working correctly, the old system will be removed completely and users will depend solely on the new system.
The phrase parallel running can refer to the process of changing a fragment of business information technology operation to a new system or to the technique applied by the human resources departments in which the existing staff stay on board during the transition to a new staff.
Overview
The new system needs to be implemented once it has been built and tested so that it is carrying out the jobs well according to the objectives. This involves a few initial steps which are:- ensuring the correct hardware and software have been prepared; any additional hardware and software are prepared and stored until they are implemented. Before setting up the hardware and so
The process
Advantages
Parallel running allows results to be compared to ensure that the new system is working without any errors. If errors are found, user can refer to the old system to resolve the problem and make modifications to the new system thus operation can continue under the old system while the problems are sorted out. This also allows training of staff and help them to gain confidence in the new system.Disadvantages
The cost of implementation is very expensive because of the need to operate the two systems at the same time. It is a great expense in terms of electricity and operation costs. This would be prohibitive with a large and complex system. Parallel running implementation also requires a lot of time and needs frequent maintenance. This will slow production in a firm as workers need to do twice their normal workload for a period of time in order to achieve the same goal for both systems. This involves inputting or changing the same data for both systems to ensure the information are identical in both systems.Examples of parallel running implementation
The practical example of parallel running in human resource management is job placement. New staff and old staff work for the same job. If the new staff's performance is OK, the existing staff may not be needed any more, and will be replaced. Another example is when a new firm which undergoes change in ownership and wants to recruit new staff to operate the firm. Making the change all at once can cause problems if the new staff do not know the basics of the operation. For this reason the firm will keep the existing staff on board for a specified time to do their normal jobs while the new staff shadows them and gets the hands-on experience they require. Once the results of the new staff match the results of the existing staff in terms of productivity and operational jobs, the existing staff can be let go. Many business firms use the strategy of parallel running as a way to ensure that the computer software are capable of doing the tasks it is designed for. The old software and the new software receive the same input from the business firm. The outputs from both software programs are compared after a period of time to make sure the transition to the new system completely are fault free. Another example is a publishing firm which is producing textbooks. They decide to run the accounts part of the business by investing in a new computerized system. The existing account system is outdated and is not suitable for use with new hardware. The new system is implemented using parallel running strategy so all accounts and invoices have to be handled both in the new and old systems. If the new system does not function correctly, data from the old system can be used. However, everything needs to be done twice, which will slow down the accounts department and cost money in hiring more staff. This system is safe and the new system can be precisely tested as every transaction can be compared with the result from the old system. It is also applied when using a new computerized system to create brief reference records and generate orders but maintaining the old manual system for final financial control until the new system has been confirmed that it can function correctly.Post-implementation review
After implementing the new system, comes the post-implementation review phase which normally takes place three to six months. The review is conducted to:- determine whether the objectives of the new system have been met; if the new system is running differently from the proposed objectives, the problems need to be determined and further modifications to the new system should be carried out. This is to make sure that the new system is capable of doing the tasks it is designed for.
- ensure that the users are using the system correctly; the reports should fulfil their purposes.
- make sure the system is maintainable and flexible; further improvement and additional features to the new system can be done
- determine the flaws in the development process so that future systems can be improved; avoid the same mistakes from happening again
Other methods of implementation
Direct changeover is when the old system is completely removed and immediately replaced by the new system. This option is risky as there may still be problems with the new system. It is the cheapest and simplest form of changeover but if something goes wrong, the user cannot fall back on the old system. The staff must be fully trained in advance and all the files must be input to the new system before it goes live. In phased implementation, the system is introduced gradually. Parts of the old system are replaced while the remaining parts are still running in the old system. As an example, a school was introducing Management Information System for all aspects of the school's operation. It could introduce the enrolment system, then four months later the examinations system and in a further four months the timetabling system. As each new module is activated and confirmed to be functioning correctly, the next module can be installed. It is likely that some modules will work with each other. For example, the timetable module assume we have all the students data and so the order in which they are introduced must be considered. Pilot running is when the new system is installed for only a small number of users to test and evaluate the new system. The new system is implemented for all the users once it is considered that it has been fully tested and able to function correctly. The test users can assist in training others on how to use the new system. This implementation strategy is very useful for a system with a large number of users because it can ensure that all the users can use the system effectively.