Nope, they just use rule of thumb. Power back goes down slowly. Power back air brakes out goes down quickly. Power up air brakes out J*s*s Chr*st descent.
Seriously, yes they do. Simple though. FL27,000 aim at 3,000 fps, level 3,000 = 24K/3 = 8 min. Speed average say 400k therefore 6 2/3 mile/min so descend at 53 miles, more likely 55-60 and ease the descent in the last 3-4 miles.