Installation Process

1.1.5 Alternative installation processes

IB Subtopic

One critical decision when moving from an old system to a new one is the choice of implementation (conversion, changeover) method. Change over is the process of putting the new system online and retiring the old one. The reason for an organization to choose one implementation method in favor of another is often a trade-off between costs and risk. It should be mentioned that in most cases there might be resistance by employees or customers to change and planning should try to minimize the negative effects.

The types of changeovers are:

• Parallel
  • Both systems work together for a short period of time, during which the new system is being slowly used more than the older one. Users can ensure that the new system is working properly by checking that expected functionality between old and new are similar. If something goes wrong, it is easy for the company to go back to the old system.
• Big Bang
  • Once a new system has been decided, the old one is completely removed and the new one is implemented.
• Pilot
  • This method calls for a small part of the organization or user-base to use the system before everyone else. After the system is successful in the pilot group or site, then the rest of the users can be brought on board.
• Phased
  • This method calls for different parts of the system to be converted over time. Eventually the whole system would be replaced.