ABSTRACT
In trying to understand why things go wrong in complex systems, the safety specialist has traditionally looked at the functioning or breakdown of carefully isolated parts or phenomena. How is it that the pilot did not notice a speed decay? How can it be that the nurse did not see the bold-printed warning EPIDURAL ONLY on the infusion bag? Why did a piece of insulating foam separate from the left bipod ramp section of the Space Shuttle Columbia external tank at 81.7 seconds into the launch?
