In engineering, a requirement is a singular documented physical and functional need that a particular product or service must be or perform. It is most commonly used in a formal sense in systems engineering, software engineering, or enterprise engineering. It is a statement that identifies a necessary attribute, capability, characteristic, or quality of a system for it to have value and utility to a user.
In the classical engineering approach, sets of requirements are used as inputs into the design stages of product development. 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. This is reflected in the waterfall model of the software life-cycle. However, when iterative methods of software development or agile methods are used, the system requirements are incrementally developed in parallel with design and implementation.
Requirements engineering is the set of activities that lead to the derivation of the system or software requirements. Requirements engineering may involve a feasibility study, or a conceptual analysis phase of the project and requirements elicitation (gathering, understanding, reviewing, and articulating the needs of the stakeholders) and requirements analysis, analysis (checking for consistency and completeness), specification (documenting the requirements) and validation (making sure the specified requirements are correct).
Read more about Requirement: Origins of Term, Product Versus Process Requirements, Requirements in Systems and Software Engineering
Famous quotes containing the word requirement:
“The first requirement of politics is not intellect or stamina but patience. Politics is a very long run game and the tortoise will usually beat the hare.”
—John Major (b. 1943)
“The work of the political activist inevitably involves a certain tension between the requirement that positions be taken on current issues as they arise and the desire that one’s contributions will somehow survive the ravages of time.”
—Angela Davis (b. 1944)
“Reporters for tabloid newspapers beat a path to the park entrance each summer when the national convention of nudists is held, but the cult’s requirement that visitors disrobe is an obstacle to complete coverage of nudist news. Local residents interested in the nudist movement but as yet unwilling to affiliate make observations from rowboats in Great Egg Harbor River.”
—For the State of New Jersey, U.S. public relief program (1935-1943)