The paper presents a historical perspective of the Qualis system in the Engineering I area of Capes. Qualis is the set of procedures used by Capes to stratify the scientific production of Brazilian graduate programs. The result of Qualis is a list of journals used by these programs for the dissemination of their intellectual production. The Qualis system began in the triennial evaluation from 1998 to 2000 and was applied with the same configuration up to 2006. In 2007 the Qualis system had an important transformation in its structure. It now has seven strata. This new Qualis was used for the first time in the evaluation of graduate programs in 2010. The new Qualis strongly uses the ISI impact factor for stratification, mainly for the two highest strata. The principles of Capes that pertain to Qualis and its application to the Engineering I area are described. Two theoretical models for the development of a histogram of journal classification are discussed: one bimodal and the other a single modal, quasi-symmetrical approach. In the field of Engineering I, the application of the Qualis criteria resulted in a bimodal histogram that approximates the theoretical model for two populations with a hierarchy of quality. A brief discussion of the impact of the new Qualis on Brazilian journals is also presented and suggestions are made for a policy which gives greater value to these periodicals.