Even before Claussen began pushing his architectural vision, others were busy designing the inner workings of the plant. Jan Knau, an engineer, was only 27 when he was asked to come up with a flexible assembly line for the factory. Knau, then just a junior associate, contacted BMW’s top 15 assembly engineers. He invited them to a two-day workshop at a BMW retreat near the Austrian Alps. After a series of marathon sessions that included discussions of every facet of the ideal assembly line, Knau…