Redmine

I'm looking for a way to do versions of versions. The situation is that I have a team of different disciplines (HW, SW, and FPGA) and I'd like to have them each have their own project with appropriate versions to work to and then wrap everything up into a "project version" like this...

PRJ = SW + HW + FPGA

...where I could set up each project to be running on it's own versions...i.e. HW-0, HW-1, SW-0, SW-1, FPGA-0, FPGA-1, etc. and then easily collect these up into "Project-level" versions...PRJ-0, PRJ-1, etc. by collecting up versions from the sub-projects...i.e...

PRJ-0 = HW-0 + HW-1 + SW-0 + FPGA-0 + FPGA-1 + FPGA-2
PRJ-1 = SW-1 + SW-2 + FPGA-3
...etc...

Of course this could be done using "multiple versions" and then a developer would select both "PRJ-0" and "HW-0" as the versions for a particular task, but I'd like to keep the developers focused on their discipline and associated versions and not on the project-level. It seems like there should be a way to associate a version from a sub-project into a version at a higher-level automatically. Any thoughts/insights/ideas are welcome...