Introduction. With the idea of combining production and educational spaces into a single space came a need to create compatible systems for assessing the level of professional preparedness of graduates of secondary vocational education organisations both in the system of domestic and foreign vocational education. The pairing of official procedures for state final certification and independent assessment of qualifications is one of the solutions. Despite the fact that this conjugation has been tested many times, it lacks a coherent scientific justification. Aim. To provide a coherent scientific justification for combining the procedures of the state final certification with independent assessment of qualifications in a professional educational organisation. Methods. The methodological basis of the study was made up of systemic, competence and qualimetric approaches, which made it possible to determine the main elements of the assessment system and their interrelations, to identify the components of the assessment that reveal the essence of the professional training, as well as to determine the technological aspects of the assessment procedure itself. Among the main methods of research are bibliometric analysis of scientific publications and the study of the practice of applying procedures for assessing the level of professional preparedness of graduates of secondary vocational education organisations. Results. An analysis of the possibilities of combining the procedures of state final certification and independent assessment of qualifications made it possible to find points of interface of assessment objects and evaluation procedures. The data obtained allowed for the development of the author's model of a unified system for assessing the professional preparedness of skilled workers, graduates of professional educational organisations. Practical significance. The technology of combining the procedures of the state final certification with independent assessment of qualifications discussed in the article allows for the usage of the author’s model of a unified system for assessing the professional preparedness in the work of both secondary vocational education and higher education. Funding. The research was carried out with the financial support of the Ministry of Education of the Russian Federation as part of the scientific project "Theory and Methodology of the Formation of a Content Update System in the Framework of Teacher Training in the Conditions of the Russian Economy Transformation"