An incremental Parallel Upgrade approach does not eliminate the responsibility of testing the upgrade process in a test environment before attempting to upgrade the production environment. It is recommended to test each of the upgrade phases in a test environment in the same order that is planned for the production environment. This can help identify issues in the solution or with the upgrade plan itself.
As components are upgraded, they should be tested in each expected state of operation. This requires careful planning and documentation of the upgrade steps.
For information on creating an OnBase test environment, see the Creating an OnBase Test Environment document found in the Resources section of the OnBase Upgrades Technical Community on the Hyland Community site.