The article is devoted to the description of the solution of the problem of substantiating the technology of wood harvesting, using simulation modeling of production processes on Petri nets. The possibility of using specially developed simulation models for the operation of forestry machine complexes consisting of a harvester and forwarder is con-sidered, not only for making decisions on the choice of machines for the formation of complexes, but also for justifying technological solutions. The solution of the problem is described in the example of a plot of irregular shape with a long trail of considerable length. The basis of the used approach is the use of the method of discrete-event simulation on Petri nets. The results of field research, modeling and improvement of the technological process are given. The results of the simulation has showed that the forwarder is loaded unevenly under the conditions of the considered cutting area . The simple of this machine was 24.5 hours or 7% of the time. A down-time of harvester was 9 hours or 3%. As a result of analyzing the simulation of the machine downtime distribution over time, it was found that this was due to the constantly decreasing forwarder performance, due to the increasing distance of skidding. As a result of the carried out research, it has been recommended to make a change in the technology for the development of the cutting area, consisting in the fact that the harvester does not start with the apiaries which are close to the loading platform, but from distant ones at the end of the main line. Modeling performed after the introduction of changes into the model has showed that in case of a shift to the proposed technology for cutting logging, productivity of harvester + forwarder machine complex can be increased by 2.3% by reducing the total downtime of the machines. It is possible to recommend the use of such technology in case of logging sites with a long haul of considerable length. Thus, when solving the real production problem, the effectiveness of the proposed approach to the evaluation of options for technological solutions for logging
harvesting, logging machine systems, harvester, forwarder, simulation, Petri nets
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