Sun-Tzu, arguably the greatest writer of all time on the subject of warfare, said that his enemy must not know where he wants to give battle. He wrote of his opponent: “For if [the opponent] prepares to the front his rear will be weak, and if to the rear, his front will be fragile. If he prepares to the left, his right will be vulnerable and if to the right, there will be few on his left. And when he prepares everywhere he will be weak everywhere.”23 Do you think Sun-Tzu advocated a Cost World or a Throughput World approach to warfare? Where should his enemy prepare?