Editing Hand formula (section)

== Use in practice ==
In the U.S., juries, with guidance from the court, decide what particular acts or omissions constitute negligence, so a reference to the standard of ordinary care removes the need to discuss this conceptual formula. Juries are not told this formula but essentially use their common sense to decide what an ordinarily careful person would have done under the circumstances. The Hand formula has less practical value for the lay researcher seeking to understand how the courts actually determine negligence cases in the United States than for the [[jury instructions]] used by the courts in the individual states.{{Citation needed|date=September 2020}}

Outside legal proceedings, this formula is the core premise of [[insurance]], [[risk management]], [[quality assurance]], [[information security]] and [[privacy]]{{clarify|date=July 2015}} practices.  It factors into [[due care]] and [[due diligence]] decisions in business risk.  Restrictions exist in the cases where the loss applies to human life or the probability of adverse finding in court cases. One famous case of abuse by industry in recent years related to the [[Ford Pinto]].

Quality assurance techniques extend 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.