The effective functioning of any socio-economic system, its financial and economic outcomes are directly related to the human factor. Man as a complex open system, as the main driving force of the socio-economic system is сonsidered. The article concerns people from controlling and controlled subsystems. On the basis of synergetic approach and the analysis of the content of concepts of «synergetics», «synergy», «synergistic effect», occurrence of synergism in practical activity of an individual, in the process of management and self-management are revealed.
The results of long-term monitoring of the activity of pairs of salesmen working in shifts in one of the shops in Lviv are described. The shop specializes mainly in selling meat and sausage products. The article deals with facts that during the working day one seller serves on average 330 customers, and the other – 282, weekly sale proceeds are significantly different, respectively. The reasons for this difference are revealed. The relationship of the seller’s individual synergy with the levels of revenue is proved using scientific methods of research, such as observation, comparison, matrix, factor, graphical analyzes, statistical methods, in particular. The positive economic effect, which was obtained mainly due to the synergy of internal and external characteristics of sellers, is substantiated on the basis of specific data of weekly earnings. It is argued that such synergy is achieved due to self-organization and effective implementation of two managerial functions by the sellers – customer management and self-management, based on the principle of compromise of interests. It is shown that a person achieves synergetic effect combining his physical, intellectual, spiritual, psychic, communication qualities and one-vector orientation of these qualities.
Manager’s actions and decisions, based on a synergistic approach are described. The choice of the seller with a similar self-organization to one, who served more customers on average, led to a significant change in the situation. As a result, their target functions have become practically equal and reached maximum or close to maximum value. This is proved on the basis of statistical methods and illustrated graphically.
Attention is drawn to the fact that finding specific opportunities that lead to synergistic effects is often not a simple matter, since it requires a wide range of knowledge, in particular, in economics, mathematics, logic, psychology, pedagogy, and sociology. A large range of situations in which there is the possibility of creating a synergistic effect in the result of individual’s activities, expand the field of scientific research. 

system, synergy, man, management, synergetic effect