sentences:  The notion was introduced during Lenin's New Economic Policy (NEP) period.However, the notion of "profitability" tended to favor light industry over heavy industry, which was hindered on the pretext of "poor profitability".Since the priority in development of heavy industry and capital goods to ensure fast modernisation of the Soviet Union was among the major sciences of the Marxist-Leninist application of Marxist economics to the Russian situation, by the end of the 1920s the notion of economic profitability was subordinated to the demands of an economic plan (), which in its turn was put into a direct dependence on political decisions and whose "control figures" were turned from guidelines into obligatory targets expressed in the series of "Five-Year Plans".