Editing Waterfall model (section)

{{Short description|Modelling a project in sequential phases}}
{{EngvarB|date=January 2023}}
{{Update|date=October 2021}}

The '''waterfall model''' is a breakdown of developmental activities into linear [[sequence|sequential]] phases, meaning that each phase is passed down onto each other, where each phase depends on the deliverables of the previous one and corresponds to a specialization of tasks.<ref name=:0/>
This approach is typical for certain areas of [[engineering design]]. In [[software development process|software development]],<ref name=:0>{{Cite book|last1=Petersen|first1=Kai|last2=Wohlin|first2=Claes|last3=Baca|first3=Dejan|title=Product-Focused Software Process Improvement |chapter=The Waterfall Model in Large-Scale Development |date=2009|editor-last=Bomarius|editor-first=Frank|editor2-last=Oivo|editor2-first=Markku|editor3-last=Jaring|editor3-first=Päivi|editor4-last=Abrahamsson|editor4-first=Pekka|chapter-url=http://urn.kb.se/resolve?urn=urn:nbn:se:bth-8073|series=Lecture Notes in Business Information Processing|volume=32 |language=en|location=Berlin, Heidelberg|publisher=[[Springer Science+Business Media |Springer]]|pages=386–400|doi=10.1007/978-3-642-02152-7_29|bibcode=2009pfsp.book..386P |isbn=978-3-642-02152-7}}</ref>
it tends to be among the less iterative and flexible approaches, as progress flows in largely one direction (downwards like a [[waterfall]]) through the phases of conception, initiation, [[analysis]], [[Software design|design]], [[Software construction|construction]], [[Software testing|testing]], [[Implementation|deployment]], and [[software maintenance|maintenance]].<ref>
{{cite journal
|author=[[Tom Gilb]]
|title=Evolutionary Delivery versus the 'waterfall model'
|journal=ACM SIGSOFT Software Engineering Notes
|volume=10
|issue=3
|pages=49–61
|doi=10.1145/1012483.1012490}}
{{open access}}
</ref>
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<ref>{{Cite web|title=The Traditional Waterfall Approach|url=https://www.umsl.edu/~hugheyd/is6840/waterfall.html|access-date=2022-02-23|website=www.umsl.edu}}</ref>
{{better source needed|date=January 2023|reason=The page referenced is a personal page from a university website with a big disclaimer at the bottom that it's not endorsed by the university.}} 
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The waterfall model is the earliest systems development life cycle ([[Systems development life cycle|SDLC]]) approach used in software development.<ref>
{{cite book
|author=Linda Sherrell
|chapter=Waterfall Model
|title=Encyclopedia of Sciences and Religions
|journal=Encyclopedia of Sciences and Religions (A.L.C. Runehov; L. Oviedo (Eds.))
|date=2013
|pages=2343–2344
|publisher=[[Springer Science+Business Media |Springer]]
|location=[[Dordrecht]], The Netherlands
|doi=10.1007/978-1-4020-8265-8_200285
|isbn=978-1-4020-8264-1
}}</ref>
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When it was first adopted, there were no recognized alternatives for knowledge-based creative work.<ref>
{{cite conference
|title=Designing for knowledge maturing: from knowledge-driven software to supporting the facilitation of knowledge development
|author1=Andreas P. Schmidt
|author2=Christine Kunzmann
|conference=i-KNOW '14: Proceedings of the 14th International Conference on Knowledge Technologies and Data-driven Business
|date=September 16, 2014
|issue=10
|pages=1–7
|doi= 10.1145/2637748.2638421
|publisher=[[Association for Computing Machinery |ACM]]
}}</ref>