A black swan event is an incident that occurs randomly and unexpectedly and has wide-spread ramifications.
The phrase represents the danger of inductive reasoning. Inductive reasoning makes broad generalizations from specific observations. For example, if a man saw a thousand swans and they were all white, he might conclude that all swans are white. The danger of inductive reasoning, however, is that even if all the premises are true, the conclusion can still be false. In other words, just because the man has never seen a black swan, it does not mean they do not exist.
The phrase "black swan" was popularized in relation to business upheaval by professor and statistician Nassim Nicholas Taleb in his 2001 finance book Fooled By Randomness. Taleb expanded beyond on the concept in his 2007 book The Black Swan, pointing out that human beings place too much weight on the odds that a past event will repeat itself.
According to Taleb, black swan events reveal:
- The fact that an organization cannot predict rare events using computer systems or scientific methods.
- The fact that once an unpredictable event has occurred, humans will conclude it was bound to happen.
- The fact that there is collective blindness to the immense role black swan events play in historical affairs.
Black swan events are extremely difficult to predict and often can only be rationalized after the fact. In information technology, a black swan event could force technology departments to reassess all of their organization's assets, strategies and resources -- everything from infrastructure to business continuity planning to security teams -- in an effort to avoid being blindsided again.