Please help me in upgrade approach finalization, i am providing brief about environment
1.CA SDM Version 12.5
2. 6 secondary sever
3. Patches installed
4. Site specific customization available
5. Advanced Web adaptation available
if possible please refer any KB article if available.
You may refer below document for planning and implementing 14.1 migration:
How to Upgrade CA SDM - CA Service Management - 14.1 - CA Wiki
Please follow this technical document on the steps to setup test box using swing box method, followed by steps to migrate.
You may also refer to " How to Upgrade CA SDM" from product documentation.