I have to disagree with all this... I think that while the supply system is not perfect, you are probably not playing realistically either... I have just played an rc11 Italy '36 game and have had none of these supply issues - other than what I would realistically expect.
Things you probably shouldn't do:
1) rebase your entire fleet in Africa. For some reason Ships use a lot of Fuel. Perturbing this is.
Fleets are in ports, ports are where supply get shipped, if I station my fleet in Tripoli but the supply depot is in southern Egypt, is it WAD that the fuel is send to Alexandria to the depot and _then_ back to Tripoli, instead of directly from Italy to Tripoli.
Also fleets that doesn't move use a lot less fuel than a fleet that patrols.
2) rebase a huge chunk of your AF in Africa. Ironically it also tends to use fuel.
Agreed, you can get fuel or supplies only in so huge amounts over African camel roads.
3) Drive around the middle of the Congo with your Armd corps. After all, it would be so plausable in real life to drive around in the middle of Africa in 1940 with an Armd force & expect it to be supplied.
I don't mind that the last piece of road is red hatched, if all ports are used and the supplies aren't first shipped(by road) to the other end of the continent and then back.
Things you should do:
1) Use smaller, ligher forces. Ironically, that is what happened historically... You have Cav. You have Militia. You have Inf. Use them.
2) Work Africa from the outside in, not the inside out. Everyone seems to think that it would be easy to drive from Egypt to South Africa - when in reality they would go from port to port... and then link up the areas...
3) Research the tech. These made a HUGE difference...
Agree.
All in all... while the supply system is not perfect.. I think that there is more "user error" going on than game error...
There is so much of the "hey I drove 25 Armd divisions down a single dirt road 1000km inside Russia and for some reason some of them are not getting supplied anymore. Thus supply system Sucks!". Yea right.
"User errors" or "User frustration" are closely related, if you can see that your overseas supply only use 1 port (largest or closed to depot) and you got 4 others that are just lazying about gets you frustrated as user.
That a unit 1 province outside a port with a possible convoy should get supplied from the other end of the continent would be OK, if no other unit is missing supply, but if the depot is nearly empty and units are OOS then at latest should additional ports be used (there are some other considerations such as can we protect the convoy, but there is no hint about that).
I like the HoI3 supply system because its more realistic than previous version, that supply moves to the units, that it cost something to move it, that there is a limit to the amount being moved are all good features that mostly function.
However it breaks down when you supply Africa from Rome/Berlin over Bosporus instead of by ship, when there is a single depot for an entire continent, when ports are used totally illogical ie. sending the supplies to a depot far away while units close by doesn't get any.
The user(Me) can't understand how much supply/fuel is used to bring enough for one unit at Omsk from Berlin (that must be distance 2-300 from Berlin) its something like (0.1-tech+partisan+weather)*300 that's 30 supplies or so per unit??? but there is nowhere you can see that.
A unit in Tripoli supplied from Berlin over Bosporus would be distance 500 or so, limiting the entire continent to 5-10 units, supplied over convoy from Trieste the distance would be around 50, ships were just so much more efficient than rail, which was much more efficient than roads.