In addition to the whole crude oil tests performed as part of the inspection assay, a comprehensive or full assay requires that the crude oil be fractionally distilled and the fractions characterized by appropriate tests. This characterization is necessary to enable the refiner to assess the quantity and quality of products recoverable from a given crude oil and to determine if that product slate economically satisfies the market requirements of a particular refinery. Refiners tailor a comprehensive assay to their individual needs, and the number of cuts or fractions taken may vary from as few as 4 to 24 or more. The following ten fractions provide the basis for a moderately thorough evaluation: