A while back, I learned about setting flow control for resources that are shared over an entire vessel, such as RCS fuel.
Today, however, I came to wonder if I knew what I thought I knew.
My ship, Far Traveler, has a 2.5 m RCS tank in the transfer stage (250 units), four "roundified" external tanks on the lander ascent stage (60 units), and the usual 10 units stored in the command pod. On its first real mission, I never had a problem with RCS until after decoupling the transfer stage to test the lander during aerobraking -- and then I found out both the lander's roundified tanks and the small capacity of the Mk. 1 command pod were depleted.
Now, either I ran everything dry just about the time I decoupled (unlikely, since I was turning off RCS between intentional uses to avoid having it cause orbit drift when used for stability, though I can't say I actually checked; last time I'd looked, after using RCS for a very, very small correction burn, there was about 40% left), or my flow priority (30 for the transfer stage tank, 10 for the roundified tanks, and -10 for the command pod's tank) worked backward from what I expect.
Suggestions?