A method of establishing a datum reference frame for a manufactured detail part used in an assembly comprises establishing a primary datum reference plane, identifying first and second mating surfaces of the part, identifying first and second functional features of size on the first and second mating surfaces, using a coordinate measuring machine (CMM) probe to identify a first point at an intersection of a centerline of the first feature and the first surface, using the CMM probe to identify a second point at an intersection of the centerline of the second feature and the second surface; and establishing a secondary compound datum reference plane through the intersection points and perpendicular to the primary datum reference plane.