Conformity assessment procedures provide a means of ensuring that the products, services, or systems produced or operated have the required characteristics, and that these characteristics are consistent from product to product, service to service, or system to system. Conformity assessment includes: sampling and testing; inspection; certification; quality and environmental system assessment and registration. It also includes accreditation of the competence of those activities by a third party and recognition (usually by a government agency) of an accreditation program's capability.

While each of these activities is a distinct operation, they are closely interrelated. The inclusion or absence of any of these activities, as well as the quality with which any one of them is performed, can have a significant effect on the confidence and reliance that can be placed on the results of the entire conformity assessment process. In addition, standards, which underlie each of these activities, can also have a major impact on the outcome of each specific conformity assessment activity as well as a cumulative effect on the outcome of the entire process within the Certification Scheme.

Conformity assessment activities form a vital link between standards (which define necessary characteristics or requirements for products) and the products themselves. Together standards and conformity assessment activities impact almost every aspect of life in the United States.

Conformity assessment can verify that a particular product meets a given level of quality or safety, and provide the user with explicit or implicit information about its characteristics, the consistency of those characteristics, and/or performance of the product. Conformity assessment can also increase a buyer's confidence in a product, furnish useful information to a buyer, and help to substantiate a company's advertising and labeling claims regarding a product. Conformity assessment is therefore an important marketplace communications device -- a means of exchanging information between buyer and seller. It is vital for buyers, sellers, and other interested parties to understand the conformity assessment process to competently judge the value of a particular assessment scheme and to use the information resulting from that scheme to make intelligent marketplace choices.

The quality of the conformity assessment information conveyed depends on: the impartiality and competence of the assessment body; the types of assessment activities included in the scheme; and the adequacy and appropriateness of the standards against which the product is evaluated. Improperly conducted conformity assessment activities may result in widespread buyer deception. If properly conducted, however, conformity assessment can furnish valuable information to the marketplace and can serve as the basis for increased opportunities for national and international trade.

The impact of conformity assessment on both domestic and international trade was prominently noted in the 1994 Agreement of Technical Barriers to Trade (TBT Agreement) of the international General Agreement on Tariffs and Trade of the World Trade Organization (WTO). The TBT Agreement recognized that conformity assessment activities can expedite or seriously hinder the free flow of goods in international commerce and established procedural requirements for conformity assessment schemes to avoid the establishment of unnecessary obstacles to trade. The agreement requires that conformity assessment procedures be "prepared, adopted and applied so as to grant access for suppliers of like products originating in the territories of other Members [signatories to the agreement] under conditions no less favorable that those accorded to suppliers of like product of national origin or originating in any other country." The Agreement also requires that such procedures not be "prepared, adopted or applied with a view to or with the effect of creating unnecessary obstacles to international trade." Ideally, a properly conducted conformity assessment program benefits, not hinders, the free flow of goods into the marketplace.