the use of probability and loss to include uncertainty bounds in each quantity and possible interactions between uncertainty in probability and impact for two purposes. First, to more accurately model customer acceptance and process reliability to produce wanted outcomes. Second, to seek cost effective factors either up or down stream of the event that produce better results at sustainably reduced costs. Example, simply providing a protective rail near a cliff also includes quality manufacture features of the rail as part of the solution. Reasonable signs warning of the risk before persons reach the cliff may actually be more effective in reducing fatalities than the rail itself. Australia In Australia, the calculus of negligence is a normative judgement with no formula or rule. In NSW, the test is how a reasonable person (or other standard of care) would respond to the risk in the circumstances considering the 'probability that the harm would occur if care were not taken' and, 'the likely seriousness of the harm', 'the burden of taking precautions to avoid the risk of harm', and the 'social utility of the activity that creates the risk of harm'. State and Territory legislatures require that the social utility of the activity that creates the risk of harm be taken into account in determining whether or not a reasonable person would have taken precautions against that risk of harm. For example, in Haris v Bulldogs Rugby League Club Limited the court considered the social utility of holding football matches when determining whether a football club took sufficient precautions to protect spectators from the risk of being struck by fireworks set off as part of the entertainment during a game. References Tort law Law and economics Legal doctrines and principles