I had a DGen campaign all worked out on paper but never had the time... but I'll part with some thoughts..
- Japan needs the raw materials from it's conquered countries to survive. Convoys (and ship numbers) are important for it's survival. Every fully laden ship returning home adds to the points pool.
Points are allocated to:-
1) Ship building
2) Aircraft building
3) Army supplies - troopships reinforcing territories
Convoys travel back and forth...
YOU are COMSUBPACs strategist, and you manage your subs.
You might allocate points to your pool, by the points value of the ships sunk(more challenging), or just have an infinite, steady influx of points from the mainland (as it was).
As the strategist, you allocate your sub fleets patrols watching them move on the BIG map. So there you are drinking your beer when on the map, one of your subs starts flashing - CONTACT...???
When you click on the flashing sub... DGEN writes single mission/patrol files relevant to this action.. off you go to the single mission 'activity' and the action starts.
At the end on the action which can be anytime, you exit - DGEN analyses the report and updates the relevant stuff,... the AI takes over you sub again (heaven forbid)... and you're back to your beer, and re-routing other subs to intercept...
As you can see.. you can now play multiple subs in many areas 'simultaneously' - you'll be very busy.
I've yet to work out what happens when many subs flash on the map at once..
Maybe throw in a bit of simple code breaking as well
;---------------------------------------------------------------
Assuming all works out well with the DGEN, you could have a battle on your hands. If you don't sink enough ships.. you'll see more aircraft and enemy ships.... making life very difficult.
This is from the Allied POV, and an AXIS DGen can also be made.
Maybe I should put some time into this