At this point resource units are delivered to their shipping lane destination world, and the necessary RUs are deducted from their origin worlds.   Shipping lanes are exercised in the order you define, so if the there is not sufficient RU stockpiled on a world to meet its shipment needs, the lower priority lane shipments will simply fail for the turn. If a world is blockaded, no RUs can be shipped from it. Note that a blockaded world can still receive RUs shipped to it. Any persistent shipping lanes will resume normal operations when the blockade is removed. Any unshipped RUs remain stockpiled, without spoilage, and carry over to the next turn.