Apparently there was an air bubble somewhere in their fuel system that was turning this rather simple routine into an all-day affair of filling up and emptying out jerry cans.
But it is notoriously ill-suited to high-tech industries that have to tailor each item to a customer's specific needs (as in a data-switching centre or air-traffic-control system) or in which it is crucial that thousands of interrelated components all work correctly together (as in a rocket vehicle).