(11)Both quantitative and qualitative factors should be used to produce a mapping, with the qualitative factors being considered in a second stage, as and when necessary and especially where quantitative factors are not adequate. As a result qualitative factors should assist in reviewing, correcting and enhancing any initial mapping done based on quantitative factors, where such review is justified and necessary. This two-step approach is required in order to contribute to the objectivity of the mapping and to ensure that the mapping actually represents the correspondence of the rating categories of an ECAI with a regulatory scale which has been defined for prudential purposes.