Versioning during engineering

Hi, we are using PCS7 (V9.0) and we are wondering what the best way is to simultaneously work on multiple versions of our project.

We have automated an experimental/test plant, and we frequently need to make small changes to the logic, in the CFC's, for instance adding an interlock or changing a gradient. We're still learning how to optimize our plant since we're the first to do this.

At the same time, we're working on a larger project to perform automatic startup, using SFC types. We found it easier to use SFC types than SFC charts since types offer for instance easier messaging. The SFC "instances" are of course connected to IO's of the impacted charts (motors, valves, instruments). Some of these connections between SFC instance and the CFC blocks require changes to the current logic (such as activating a gradient or overwriting a MV in certain conditions) which means when we make these links, we have to cut existing links and add select blocks, or ports etc. This is error-prone and we don't want to do this during "production". Therefore, we only test (and deploy) these automatic startup changes during specific time windows.

The main problem we face is that since this is a big project and we work with these time windows, some of the impacted CFC's (so the valves, motors etc) may have had small changes in the logic for operational reasons, as described above since last time we tested.

Today we take a backup after each time window, start working on that backup for the automatic start up, and when there's a new test window we merge all operational changes manually. I can't imagine this is the best way to do this.

Is there a way to do project engineering on different versions of a project, that allows to merge two versions of a CFC and for instance show conflicts between two versions of the same chart?