A white paper, published by EUROCONTROL’s Network Manager and entitled “From Safety I to Safety II”, explains the key differences between, and the implications of, two different ways of thinking about safety.
Sources:
http://www.eurocontrol.int/news/safety-focus-what-goes-right
http://www.skybrary.aero/index.php/Main_Page
http://www.eurocontrol.int/articles/safety-and-human-performance-library