Methods of implementation of new or updated systems list system implementation methods compare the advantages and disadvantages of system implementation methods

Methods of implementation of new or updated systems

Typically there involves a conversion from an old system to the new system.
There are four typically methods for installation or conversion:

  • Direct changeover
  • Parallel conversion
  • Phased conversion
  • Pilot conversion

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 company immediately Most risky 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 old one working while new one is being switched on
  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 system 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 continued 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
  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;
  • Overtime 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
  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 a 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
Extra work for IT staff who are having to support two different systems



1. Name four methods of new system implementation.

2. Explain advantages of the direct method over the parallel method.


Ex. 1

Ex. 2

Ex. 3 (Author: Tashenova Dinara - CS teacher of NIS Uralsk)

Ex. 4 (Author: Tashenova Dinara - CS teacher of NIS Uralsk)

Exam questions:


Категория: Stages of SDLC | Добавил: bzfar77 (03.11.2020)
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