<blockquote>Chapanis had recognised that human beings’ propensity to make mistakes when they are tired is much harder to fix than the design of levers. His deeper insight was that people have limits, and many of their mistakes are predictable effects of those limits. That is why the architects of CRM defined its aim as the reduction of human error, rather than pilot error. Rather than trying to hire or train perfect pilots, it is better to design systems that minimise or mitigate inevitable human mistakes.</blockquote>