High-tech enterprises, possessing advanced technologies, are able to play a strategic role in ensuring the long-term, sustainable development of the national economy. This role is determined by the contribution of scientific, technical, production and personnel potentials of high-tech enterprises. A distinctive feature of these enterprises is the dominance of research activities and the related need for regular updating of used production factors. The effectiveness of high-tech enterprises depends largely on the quality of the intellectual resources used. The paper presents the results of an analysis of the effectiveness of two Russian high-tech enterprises using a modified production function. Cognitive capacity is calculated as the efficiency of using intellectual resources. As well as this, an interpretation of the results is also given. The proposed modified function can be used in practical activities to support the adoption of managerial decisions on the strategic development of industrial enterprises and increase their economic efficiency.