To undertake a general overhaul ( maintenance clock reduction , not refit to an improved design ) of vessels , do the vessels have to be either :-
a) orbiting a planet with a shipyard dedicated to the applicable design
b) orbiting a planet with generic shipyards
c) orbiting a planet with maintenance supplies
d) some other parameters
advice would be appreciated so that i can spread the overhauls throughout my colonies rather than sending all vessels to earth which is becoming overwhelmed with vessels required refits as well as overhauls.
DavidR