The purpose of this paper is the development of theoretical principles for a comprehensive assessment of the efficiency of operation of combine harvesters. A comprehensive criteria for the efficiency of grain combine harvesters operation defined as the product of the criterion for the efficiency of grain combine harvesters use as intended and the criterion for their maintenance efficiency is introduced. The criterion for the efficiency of the combine harvesters usage includes the following particular indicators: the productivity of a grain combine harvester for one hour of the main time, the labour intensity, the operational fuel consumption, direct losses, crushing and macro injury of grain, and the annual load per harvester. The criterion of the efficiency of technical maintenance of combine harvesters also takes into account specific indicators, including the operational and labor intensity of maintenance, specific fund costs of maintenance, frequencies and completeness of maintenance, equipment of dealer centers with maintenance facilities, provision of repair and maintenance workshops with maintenance personnel, combustible and lubrication materials and spare parts. The efficiency criteria included into the complex one also take into account the relative importance of each specific indicator, which is determined by expertise. A scheme for the complex criterion formation and a scheme for increasing the efficiency of the combine harvesters’ usage are proposed.
Key words: complex efficiency criterion, operation, criterion of usage efficiency, maintenance, grain combine.
