When the key people in your business are happy with the new software, you can give the software vendor permission to begin the process of implementing the software. For a brand new system with no links to anything else you might find implementation to be as simple as installing the software. For replacement systems which integrate with other important computer systems then it will be very important to develop and test an implementation plan that will allow you to migrate all the existing data and update the connections to the other programs.

You should ensure that you try to preserve the ability to revert to your previous system should anything go wrong.