“Plans fail
because of what we have called tunneling, the neglect of sources of uncertainty
outside the plan itself…..The unexpected almost always pushes in a single
direction: higher costs and a longer time to completion. On very rare
occasions, as with the Empire State Building, you get the opposite: shorter
completion and lower costs—these occasions are becoming truly exceptional
nowadays…..As I said earlier, we are too narrow-minded a species to consider
the possibility of events straying from our mental projections, but
furthermore, we are too focused on matters internal to the project to take into
account external uncertainty, the “unknown unknown,” so to speak, the contents
of the unread books.” –Nassim Taleb, The Black
Swan
