Normalisation of deviance

Two reasons why safety management should never rely solely on indicators for information are the phenomena of normalisation of deviance (Vaughan 1996 cf Dekker 2011) and the drift of activities (Snook 2000). Another, third reason has to do with the complex nature of the system itself... 

Normalisation of deviance refers to a process in which small changes... 

These aberrant behaviours and actions are insidious and, if not detected and trapped through a robust safety and quality audit regimen, become unofficially sanctioned procedures. Diane Vaughan (19%), in her definitive woik on the loss of the space shuttle Challenger referred to this as the normalisation of deviance . 

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