A generic term for the complete range of checks that are performed on a system in order to increase confidence that the system is suitable for its intended purpose. This range might include a rigorous set of functional tests, performance testing, reliability testing, and so on, in which case the term verification, validation and testing (VV&T) is more appropriate. Although a precise distinction is not always drawn, the verification aspect normally refers to completely objective checking of conformity to some well-defined specification, while the validation aspect normally refers to a somewhat subjective assessment of likely suitability in the intended environment.