Managing Murphy´s law: engineering a minimum-risk system

The meanings of ´risk´ and ´risk analysis´ are examined by the author. The steps to be taken in assessing and quantifying risk are described, and the question of accepting and managing risk is briefly considered. Definitions of terms such as hazard, failure, accident and reliability are given. Two sources of uncertainty, i.e. the laws of chance and human error, are finally discussed using the Piper Alpha explosion as an example.<>