Editing Systems engineering (section)

===Scope===
[[File:SE activities (en).svg|thumb|left|upright=1.2|The scope of systems engineering activities]]<ref name="SEF01">{{cite web|title=Systems Engineering Fundamentals|url=http://www.dau.mil/publications/publicationsDocs/SEFGuide%2001-01.pdf|year=2001|archive-url=https://web.archive.org/web/20170131231503/http://www.dau.mil/publications/publicationsdocs/sefguide%2001-01.pdf<!--archive url isn't ideal-->|archive-date=2017-01-31|url-status=dead|publisher=Defense Acquisition University Press|language=en}}</ref>

The principles of systems engineering&nbsp;– holism, emergent behavior, boundary, et al.&nbsp;– can be applied to any system, complex or otherwise, provided [[systems thinking]] is employed at all levels.<ref>{{cite web|last=Adcock|first=Rick|url=http://incose.org.uk/Downloads/AA01.1.4_Principles%20&%20practices%20of%20SE.pdf|title=Principles and Practices of Systems Engineering|publisher=INCOSE, UK|access-date=7 June 2007|archive-url=https://web.archive.org/web/20070615160805/http://incose.org.uk/Downloads/AA01.1.4_Principles%20%26%20practices%20of%20SE.pdf|archive-date=15 June 2007|df=dmy-all}}</ref> Besides defense and aerospace, many information and technology-based companies, [[software development]] firms, and industries in the field of [[Electronics & Communications Engineering|electronics & communications]] require systems engineers as part of their team.<ref>{{cite web|url=http://www.gmu.edu/departments/seor/insert/intro/introsal.html|title=Systems Engineering, Career Opportunities and Salary Information|date=1994|publisher=George Mason University|access-date=7 June 2007|archive-url=https://web.archive.org/web/20070922213853/http://www.gmu.edu/departments/seor/insert/intro/introsal.html|archive-date=22 September 2007|df=dmy-all}}</ref>

An analysis by the INCOSE Systems Engineering Center of Excellence (SECOE) indicates that optimal effort spent on systems engineering is about 15–20% of the total project effort.<ref name="SEvalue" /> At the same time, studies have shown that systems engineering essentially leads to a reduction in costs among other benefits.<ref name="SEvalue">{{cite web|url=http://www.incose.org/secoe/0103/ValueSE-INCOSE04.pdf|title=Understanding the Value of Systems Engineering|access-date=7 June 2007|archive-date=15 June 2007|archive-url=https://web.archive.org/web/20070615160805/http://www.incose.org/secoe/0103/ValueSE-INCOSE04.pdf|url-status=dead}}</ref> However, no quantitative survey at a larger scale encompassing a wide variety of industries has been conducted until recently. Such studies are underway to determine the effectiveness and quantify the benefits of systems engineering.<ref>{{cite web|last=Elm|first=Joseph P.|title=Surveying Systems Engineering Effectiveness|url=http://www.splc.net/programs/acquisition-support/presentations/surveying.pdf|publisher=[[Carnegie Mellon University]]|location=Pittsburgh, Pennsylvania|archive-url=https://web.archive.org/web/20070615160805/http://www.splc.net/programs/acquisition-support/presentations/surveying.pdf|archive-date=15 June 2007|access-date=16 March 2023}}</ref><ref>{{cite web|url=http://www.valerdi.com/cosysmo/rvalerdi.doc|title=Systems Engineering Cost Estimation by Consensus|access-date=7 June 2007}}</ref>

Systems engineering encourages the use of [[modeling and simulation]] to validate assumptions or theories on systems and the interactions within them.<ref>{{Cite journal|doi=10.1177/003754970107600207|first1=Andrew P.|last1=Sage|author1-link=Andrew P. Sage|first2=Stephen R.|last2=Olson|title=Modeling and Simulation in Systems Engineering|page=90|volume=76|date=2001|journal=Simulation|url=http://intl-sim.sagepub.com/cgi/content/abstract/76/2/90|archive-url=https://web.archive.org/web/20071021061349/http://intl-sim.sagepub.com/cgi/content/abstract/76/2/90|archive-date=21 October 2007|access-date=2 June 2007|issue=2|s2cid=3016918}}</ref><ref>{{Cite journal|last=Smith|first=E.C. Jr.|title=Simulation in Systems Engineering|journal=IBM Systems Journal|publisher=IBM Research|date=September 1962|volume=1|pages=33–50|doi=10.1147/sj.11.0033|url=http://www.research.ibm.com/journal/sj/011/ibmsj0101D.pdf|archive-url=https://web.archive.org/web/20070604221716/http://www.research.ibm.com/journal/sj/011/ibmsj0101D.pdf|archive-date=4 June 2007|access-date=16 March 2023}}</ref>

Use of methods that allow early detection of possible failures, in [[safety engineering]], are integrated into the design process. At the same time, decisions made at the beginning of a project whose consequences are not clearly understood can have enormous implications later in the life of a system, and it is the task of the modern systems engineer to explore these issues and make critical decisions. No method guarantees today's decisions will still be valid when a system goes into service years or decades after first conceived. However, there are techniques that support the process of systems engineering. Examples include soft systems methodology, [[Jay Wright Forrester]]'s [[System dynamics]] method, and the [[Unified Modeling Language]] (UML)—all currently being explored, evaluated, and developed to support the engineering decision process.