History of Science and Engineering Annotation << Back Invention Activity at Leningrad Enterprises of the People’s Commissariat for Heavy Industry in 1932–1939: the Management System and Challenges of Scientific and Technical Work Aleshin V.S. This study examines a poorly researched phenomenon in the history of Soviet science – invention activity at Leningrad enterprises subordinate to the People’s Commissariat for Heavy Industry during the fi rst fi ve-year plans for the development of the USSR’s national economy. Drawing on a wide range of historical sources introduced into scholarly circulation for the fi rst time, the research systematically analyses the formation of the factory invention management system, and the key challenges faced by working-class inventors. The author demonstrates that, throughout the existence of the People’s Commissariat for Heavy Industry, invention activity – as an integral part of the factory science sector – failed to develop adequately due to the absence of a stable management system, inconsistent evaluation of inventions by all-Union, sector-specific and factory-level bodies, lengthy review periods, technological conservatism, management passivity, and the weak general educational background of many inventors. Keywords: factory science, Soviet science, industrialization of the USSR, invention in the USSR, history of the USSR, science and technology. DOI: 10.25791/intstg.8.2026.1634 Pp. 03-16.