User acceptance tests for on-premises to on-premises migration
During user acceptance tests, the cutover process is validated, and you perform a User Acceptance Test (UAT) to validate the system as acceptable for production usage.
Perform UAT in two rounds with an emulated cutover. An emulated cutover is a trial run of the go-live process. You can refine the cutover process prior to the real production cutover. The second round of UAT proves that all fixes from the first round have been successfully deployed into the Gold Build backup. The second round is intended to be a short regression test of 2-3 days prior to the final production cutover. After you complete your UATs, you are ready to go-live.
The target milestone for this phase is the UAT sign-off of the system.
An overview of the activities involved in the UAT phase is described in the following image:
Perform emulated cutover 1
The emulated cutover replicates the steps of the real production cutover as much as possible without impacting the current production service.
Perform the go-live assessment during the emulated and production cutover.
Perform UAT round 1
Perform a full application and integration testing of the system (that is, user acceptance testing). Perform the tests on the to-be-production system to ensure this environment is tested as much as possible prior to go-live.
Use documented tests to ensure that the full range of the application is tested. Develop fixes for issues on the system and create an export package.
Record all issues and fixes in a spreadsheet or fault tracking system. Then, track and copy any data or workflow changes back into the Gold Build backup.
At the end of UAT Round 1, review all open issues and decide which issues need to be resolved before go-live. Any issue fixes are deployed into the Gold Build backup in the next step.
Restore Gold Build backup and deploy UAT fixes
Restore the latest gold backup, apply all the workflow and data fixes from the UAT round 1, and take a fresh backup.
This step can only be successful if the project team has recorded all fixes and changes during UAT.
Perform emulated cutover 2
Use a fresh data set for the second and final emulated cutover and round of UAT. Refine this process after the initial test of the cutover process performed in the first emulation. The timing of this emulated cutover provides an accurate estimate of the outage duration for the real production cutover.
Perform UAT round 2 and UAT sign-off
Perform a final round of regression testing, focusing on defects found during the first round of UAT. This process should take no more than a few days to complete. After you are satisfied that the system is ready, get the required sign-offs as the last action prior to go-live.
Ideally, no further defect fixes are expected to be required at this point. For any unexpected issues, you will require an update to the Gold Build backup and further testing.