Categorias de requisitos

System Requirements Fundamentals
Introduction Requirements Development Requirements Categories Writing Better Requirements

Requirements Fundamentals - Requirements Categories

(This work is based on material from many sources, including www.ppi-int.com, Systems Engineering Course)

© André Mayoral, 2011 | helping systems happen... | all rights reserved

Importance of Requirement Types
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Different types exist. Recognizing this fact implies:
    

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Why different Types


Different fields of knowledge, Different analysis skills, Different spec techniques, Different solution techniques, Ability to change one thing without changing another
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Requirements are responsible for most project failures*:
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45% of failures due to requirements problems 2nd reason: 11%
*Source: Standish Group,1996

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All requirements problems are related to clarity of information
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Ambiguity, transcriptions, different points-of-view

 

Making distinctions brings clarity Distinct requirement types brings clarity to specs

© André Mayoral, 2011 | helping systems happen... | all rights reserved

What is the categorization criteria?
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This categorization is based on the nature of the information, not in its origin. This helps each requirement to have only one place in a spec, thus avoiding:
  

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Delays in searching for requirements Surprises: finding out that a requirement where it is not supposed to be Duplicity: having requirements in different places that:
  

Are the same, Have overlaps, Are conflicting!

© André Mayoral, 2011 | helping systems happen... | all rights reserved

Types of Requirements
( (Organize your specification using one section for each requirement type)

Category
Functional Performance States and modes Safety External Interface Environmental Resources Physical Verification Human Factors Reliability Maintainability Other Qualities Design
Manufacturability

Description: required