Efficient repair and maintenance infrastructure, which technically supervises machines and devices in production processes, has a significant impact on the improvement of efficiency of the machine and devices application in production processes. In a present situation, with the use of complex and in many cases expensive machines with high structural and quality parameters, users may significantly influence the increase of the degree of their use through optimization of time devoted to efficient repair and maintenance treatments. The fundamental objective of the paper was to analyse the time during which farm machines stay in repair shops during periodical service and maintenance in the aspect of their performance effectiveness. The index of organizational effectiveness designated for assessment of shops which carry out maintenance of machines was determined. The relation between the coefficient of technical use of a machine and the index of effectiveness of the maintenance and repair system organization in a repair shop were determined. A functional scheme of the machine operation system was presented. This scheme in a general aspect covers functional relations of main components of the service and maintenance system of shops in the aspect of quality assessment of their particular subsystems.