The approach of electrothermo analogy for the analysis of thermal processes is considered. This approach is obviously justified, since it is based on a deep physical analogy of the processes of heat propagation and electric current in various media. The study aims to analyze the distribution of heat fluxes in the system «workpiece - cutting insert - tool holder» (W-CI-TH), taking into account external and internal cooling. We present the set of parameters of the system (W-CI-TH), which gives grounds to consider them as elements of the block diagram of the control system for the thermodynamic mode of turning materials of any physical and mechanical properties, which is the subject of independent researches.