Criteria for validating software requirements
The requirement is atomic, i.e., it does not contain conjunctions.
E.g., "The postal code field must validate American and Canadian postal codes" should be written as two separate requirements: (1) "The postal code field must validate American postal codes" and (2) "The postal code field must validate Canadian postal codes".
Requirements are also an important input into the verification process, since tests should trace back to specific requirements.
Requirements show what elements and functions are necessary for the particular project.
It is commonly used in a formal sense in engineering design, including for example in systems engineering, software engineering, or enterprise engineering.
It is a broad concept that could speak to any necessary (or sometimes desired) function, attribute, capability, characteristic, or quality of a system for it to have value and utility to a customer, organization, internal user, or other stakeholder.
Traceability confirms that the requirement set satisfies the need (no more - and no less than what is required).
For example, a requirement to present geocoded information to the user may be supported by a requirement for an interface with an external third party business partner.When iterative methods of software development or agile methods are used, the system requirements are incrementally developed in parallel with design and implementation.With the waterfall model requirements are developed before design and implementation.For historical usage, see Spanish Requirement of 1513 and Requerimiento.In product development and process optimization, a requirement is a singular documented physical or functional need that a particular design, product or process aims to satisfy.