I currently have all the objects of a model driven app I'm building in a single solution. Now as the thing is growing, I'm trying to split the whole up into smaller solutions that would follow a reasonable dividion and ease deployment from DEV to PROD. Also I recently faced some solution import errors based on business rules being on/off and inability to "Upgrade solution" to the next new version in PROD environment. My current idea of the division is the following:
1 Base solution
2 Business rules and processes
3 Cloud workflows (including connection references maybe)
I'm now trying to move my business rules from the original (1 Base solution) to the new solution (2 Business rules and processes). I've added those there, so they now exist in two solutions. I'd now like to delete those from the original solution and keep updating them in solution 2. All of this is in the same (DEV) environment. How could I do that? Is it reasonable to do this type of a division?
Left photo: In the original solution I'm not able to remove those business rules from the solution, just delete?
Right photo: In the new solution I'm able to remove business rules from the solution, or delete

