Editing Safety engineering (section)

==Safety certification==
Typically, safety guidelines prescribe a set of steps, deliverable documents, and exit criterion focused around planning, analysis and design, implementation, verification and validation, configuration management, and quality assurance activities for the development of a safety-critical system.<ref>{{Cite book|last1=Rempel|first1=Patrick|last2=Mäder|first2=Patrick|last3=Kuschke|first3=Tobias|last4=Cleland-Huang|first4=Jane|title=Proceedings of the 36th International Conference on Software Engineering |chapter=Mind the gap: Assessing the conformance of software traceability to relevant guidelines |author4-link=Jane Cleland-Huang|date=2014-01-01|series=ICSE 2014|location=New York, NY, USA|publisher=ACM|pages=943–954|doi=10.1145/2568225.2568290|isbn=9781450327565|citeseerx=10.1.1.660.2292|s2cid=12976464}}</ref> In addition, they typically formulate expectations regarding the creation and use of [[Requirements traceability|traceability]] in the project. For example, depending upon the criticality level of a requirement, the [[Federal Aviation Administration|US Federal Aviation Administration]] guideline [[DO-178C|DO-178B/C]] requires [[Requirements traceability|traceability]] from [[requirement]]s to [[design]], and from [[requirement]]s to [[source code]] and executable [[object code]] for software components of a system. Thereby, higher quality traceability information can simplify the certification process and help to establish trust in the maturity of the applied development process.<ref>{{Cite journal|last1=Mäder|first1=P.|last2=Jones|first2=P. L.|last3=Zhang|first3=Y.|last4=Cleland-Huang|first4=J.|author4-link=Jane Cleland-Huang|date=2013-05-01|title=Strategic Traceability for Safety-Critical Projects|journal=IEEE Software|volume=30|issue=3|pages=58–66|doi=10.1109/MS.2013.60|s2cid=16905456|issn=0740-7459}}</ref>

Usually a failure in safety-[[product certification|certified]] systems is acceptable{{by whom|date=April 2015}} if, on average, less than one life per 10<sup>9</sup> hours of continuous operation is lost to failure.{as per FAA document AC 25.1309-1A} Most Western [[nuclear reactors]], medical equipment, and commercial [[aircraft]] are certified{{by whom|date=April 2015}} to this level.{{citation needed|date=April 2015}} The cost versus loss of lives has been considered appropriate at this level (by [[FAA]] for aircraft systems under [[Federal Aviation Regulations]]).<ref>{{cite book|url=http://www.faa.gov/documentLibrary/media/Advisory_Circular/AC%2025.1309-1A.pdf|title=System Design and Analysis|publisher=[[Federal Aviation Administration]]|year=1988|id=Advisory Circular AC&nbsp;25.1309-1A|author=ANM-110|access-date=2011-02-20}}</ref><ref>{{cite book|url=http://standards.sae.org/arp4754a|title=Guidelines for Development of Civil Aircraft and Systems|last=S–18|publisher=[[Society of Automotive Engineers]]|year=2010|id=ARP4754A}}
</ref><ref>{{cite book|url=http://www.sae.org/technical/standards/ARP4761|title=Guidelines and methods for conducting the safety assessment process on civil airborne systems and equipment|last=S–18|publisher=[[Society of Automotive Engineers]]|year=1996|id=ARP4761}}
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