A type of requirementA usable representation of a need. that describes the performance or quality attributesA set of measures used to judge the overall quality of a system. See also non-functional requirements. a solution must meet. Non-functional requirements are usually measurable and act as constraints on the designA usable representation of a solution. For more information see Key Terms (p. 14) and Requirements and Designs (p. 19). of a solution as a whole.
