The problem of ensuring the sustainability of development and growth of the sector of the national economy occupied by small and medium-sized business entities involves the search for conceptual approaches aimed at increasing the efficiency of functioning of both individual business entities and their collection. Moreover, tasks of this kind are often poorly structured, that is, based on many elements, factors, and functional interactions. This circumstance suggests the paramount importance of constructing heuristic-useful and least risky from the point of view of the possible consequences of various regulatory impacts of small and medium-sized business models, which allow adequately describing and predicting the behavior of this system.?The variety and evolution of types of entrepreneurial structures, due to the processes of complication of social and production systems in the modern world, including diversification and integration interaction, suggests the study of their comparative advantages in terms of opportunities and sustainable progressive development. In this case, a special place is given to the sector of small and medium-sized business structures as the driving force for the sustainable development of the entire national economy.