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1.3.2 On the Use of a System Need Statement in Functional Decomposition
Author(s) -
Ryan Michael J.
Publication year - 2011
Publication title -
incose international symposium
Language(s) - English
Resource type - Journals
ISSN - 2334-5837
DOI - 10.1002/j.2334-5837.2011.tb01185.x
Subject(s) - decomposition , hierarchy , functional requirement , computer science , statement (logic) , stakeholder , functional decomposition , non functional requirement , point (geometry) , process (computing) , requirements analysis , systems engineering , software engineering , risk analysis (engineering) , process management , engineering , software development , programming language , mathematics , software , business , ecology , software construction , public relations , geometry , machine learning , economics , political science , market economy , biology , law
Functional decomposition is a useful tool in developing system requirements, particularly where the desired end result is a system functional hierarchy. When decomposition begins with statements taken from stakeholder requirements documents, however, the resultant system requirements will tend to take on a structure that flows from whatever structure has been given to the parent statements by the authors of the stakeholder documents. Unless the stakeholder documents are themselves hierarchically organized, the decomposed requirements must then be regrouped into a suitable system functional hierarchy. Since functional decomposition (and derivation, for that matter) requires a start point, the direct development of a cohesive system functional hierarchy by decomposition requires a single, system‐level start point. This paper proposes an iterative process for the development of a system need statement and its formal decomposition into goals and objectives (and subsequently into system requirements in a functional hierarchy).