There is defined that the efficiency of workshop power supply networks largely determines the efficiency of the power supply system of the industrial enterprise as a whole and is determined by minimizing the reduced costs, which have two components: capital investments and the cost of electricity losses in workshop networks. Calculating the reduced costs during a technical and economic comparison of options is a labor-intensive task, since there is a large variability in the choice of circuit design, the choice of cross-sections of the conductors of the supply and distribution workshop network, as well as taking into account the design features of the workshop network. The analysis of the characteristics of the efficiency factors of workshop power supply was carried out. The basic components of the effective functioning of the workshoppower supply circuit are identified, namely: discreteness of electrical equipment; its placement in the workshop; operating modes of current-using equipment (CUE); loading schedule; ratio of the cost of electricity and the unit cost of workshop network elements. There has been determined that in any workshop power supply scheme, the duration of switching CUE on the electric power supply (CUE with a constant and variable operating mode), as well as the shape of the load schedule, largely determines the efficiency of its operation. Obtained results of a numerical experiment, when performing design of workshop networks in the DIPROPROM design institution (Zaporozhye), showed the effectiveness (3-7%) in determining the operational characteristics of workshop networks in comparison with existing engineering methods.