Modern realities of economic activity in the conditions of digital transformation of economy demand from industrial enterprises of any scale to provide search of intensive ways to increase productivity and reduce production costs. In the practice of developed countries, there are many methods to streamline economic processes, which can include lean production tools. Russian enterprises practically do not use lean technologies in their activity, which does not allow obtaining additional financial benefits from more competent use of available material and human resources. This article is devoted to the development of instrumental approaches to develop a method that will calculate the economic efficiency of the investment project to implement lean production on specific structural units of the industrial enterprise. For quantitative and qualitative evaluation of the efficiency of the investment project it is proposed to use an algorithm based on mathematical calculation of indicators. Practical application of the proposed instrumental approach will allow to substantiate the efficiency of the investment project on the introduction of lean production tools at certain departments of the industrial enterprise and will give a reasonable conclusion about its introduction at other structural units. It is offered to direct the further workings out on adaptation of the developed approach for estimation of advantages from introduction of lean production in various branches of national economy that will allow to receive more complete picture concerning efficiency of lean technologies at the various industrial enterprises, and also will give the chance to develop recommendations, taking into account branch specificity.