In general, I'd like to see a SINGLE concept that reads along the lines of:
A) how much of the world's GDP is from trade and how much is internal (Sort of like World Tamer's Handbook)
B) Determine how much of that "Trade" is spread amongst planets that are nearby. If 20% of Trin's GDP is from Trade - that's going to be a HEFTY amount of trade! But having 20% of the trade to divvy up with 10 planets gives a GM a way to gauge who the trading partners should be and why.
If one uses the trade model in GURPS FAR TRADER - the sum of all of the trade between individual pairings is greater than the whole of any given world's GDP
Point is however, that by being able to estimate trade, one can then begin to estimate the shipping required to service that trade. If you have that, and you have the number of hulls that have to be maintenance - the left over capacity of a shipyard AFTER accounting for maintenance - will let people determine how much "production" in new ship hulls any given Shipyard/starport engages in.
Just a thought. I don't need a more functional trade example per se - I tried computerizing the trade system from GURPS TRAVELLER: FAR TRADER and came away with the conclusion that if there is more than enough freight/cargo being produced available for tramp freighters, there is almost zero reason for the tramp freighter's hold to be empty or even partially empty. A world like Lunion would permit cargo capacity to almost 98% if the person is careful enough in bidding for freight lots.
I'm not certain I like the T5 version or any other version to be honest with you, but then again, I'm finicky that way.
A) how much of the world's GDP is from trade and how much is internal (Sort of like World Tamer's Handbook)
B) Determine how much of that "Trade" is spread amongst planets that are nearby. If 20% of Trin's GDP is from Trade - that's going to be a HEFTY amount of trade! But having 20% of the trade to divvy up with 10 planets gives a GM a way to gauge who the trading partners should be and why.
If one uses the trade model in GURPS FAR TRADER - the sum of all of the trade between individual pairings is greater than the whole of any given world's GDP

Point is however, that by being able to estimate trade, one can then begin to estimate the shipping required to service that trade. If you have that, and you have the number of hulls that have to be maintenance - the left over capacity of a shipyard AFTER accounting for maintenance - will let people determine how much "production" in new ship hulls any given Shipyard/starport engages in.
Just a thought. I don't need a more functional trade example per se - I tried computerizing the trade system from GURPS TRAVELLER: FAR TRADER and came away with the conclusion that if there is more than enough freight/cargo being produced available for tramp freighters, there is almost zero reason for the tramp freighter's hold to be empty or even partially empty. A world like Lunion would permit cargo capacity to almost 98% if the person is careful enough in bidding for freight lots.
I'm not certain I like the T5 version or any other version to be honest with you, but then again, I'm finicky that way.