Fuel Planning
Blueskymine, I don't know what your qualifications are but I can tell you I am not in the least surprised that airlines carry only fuel needed to meet legal requirements which certainly does not mean arriving at destination without reserve fuel plus alternate if required. To carry any more than required adds to fuel burn due to the added weight and, in some instances, would reduce payload availability where performance means a TOW below MTOW permissable for the aircraft.