For purposes of this program, conformity assessment consists of product sample testing, product certification, and quality system registration. Associated activities can be classified by level:

Conformity level: This level encompasses comparing a product, process, service, or system with a standard or specification. As appropriate, the evaluating body can be a testing laboratory, product certifier or certification body, or quality system registrar.

Accreditation level: This level encompasses the evaluation of a testing laboratory, a certification body, or a quality system registrar by an independent body—an accreditation body—based on requirements for the acceptance of these bodies, and the granting of accreditation to those which meet the established requirements.

Recognition level: This level encompasses the evaluation of an accreditation body based on requirements for its acceptance, and the recognition by the evaluating body of the accreditation body which satisfies the established requirements.

NIST operates the NVCASE program as follows:

Conformity level: Under this program NIST accepts requests for evaluations of U.S. bodies involved in activities related to conformity assessment. NIST does not perform conformity assessments as part of the program and therefore does not accept requests for such evaluations.

Accreditation level: NIST accepts requests for accreditation of conformity assessment bodies only when (i) directed by U.S. law; (ii) requested by another U.S. government agency; or (iii) requested to respond to a specific U.S. industrial or technical need, relative to a mandatory foreign technical requirement, if it has been determined after public consultation that (A) there is no satisfactory accreditation alternative available and the private sector has declined to make acceptable accreditation available, and (B) there is evidence that significant public disadvantage would result from the absence of any alternative.

Recognition level: NIST accepts requests for recognition of bodies that accredit testing laboratories, certification bodies, and quality system registrars when (i) directed by U.S. law; (ii) requested by another U.S. government agency; or (iii) requested to respond to a specific U.S. industrial or technical need relative to a mandatory foreign technical requirement if it has been determined after public consultation that (A) there is no suitable alternative available and (B) there is evidence that significant public disadvantage would result from the absence of any alternative.