HFM Application Migration Options

I'm hoping for some guidance on the best practice for migrating a HFM application's Metadata from a Development to Test environment, and then from Test to Production.

Our current set up is that we have 3 environments (Dev, Test, and Prod). All 3 environments contain our EPMA HFM application. Each HFM application is linked to a DRM application in the same environment (i.e. DRM Dev linked to HFM Dev, etc.).

The problem I have is that currently, any changes have to be repeated separately in each of the 3 DRM applications, and then exported to the accompanying HFM application. Because the changes are being made in DRM in each environment, errors are creeping in, and it also means that in some instances what goes into production is not always the same as what was signed off during UAT.