Editing Requirement (section)

{{Short description|Condition that must be satisfied for an engineered work to be acceptable}}
{{about|product and process development|other kinds of requirements|Need|and|Obligation|and|Intelligence requirement|historical usage|Spanish Requirement of 1513|}}

In [[engineering]], a '''requirement''' is a condition that must be satisfied for the output of a work effort to be acceptable. It is an explicit, objective, clear and often quantitative description of a condition to be satisfied by a material, design, product, or service.<ref>{{Cite book
 |title=Form and Style of Standards, ASTM Blue Book
|year=2012 |publisher=[[ASTM International]]
 |url=http://www.astm.org/COMMIT/Blue_Book.pdf
 |access-date=5 January 2013 }}</ref>

A [[specification]] or spec is a set of requirements that is typically used by developers in the design stage of [[new product development|product development]] and by testers in their verification process. 

With [[iterative and incremental development]] such as [[agile software development]], requirements are developed in parallel with design and implementation. With the [[waterfall model]], requirements are completed before design or implementation start.

Requirements are used in many engineering fields including [[engineering design]], [[system engineering]], [[software engineering]], [[enterprise engineering]], [[New product development|product development]], and process optimization. 

Requirement is a relatively broad concept that can describe any necessary or desired function, attribute, capability, characteristic, or quality of a system for it to have value and utility to a customer, organization, user, or other stakeholder.