Simulation of the Production Process of Timber Harvesting With the Help of Petri Nets

The article describes the approach to a substantiation of a choice of machines systems for wood harvesting, based on simulation modeling of manufacturing processes using Petri nets. Selection of groups of sites with relatively similar conditions from the point of view of technological process of timber harvesting is justified. The results of performed field investigations, modeling and improvement of processes on the example of one model cutting area are given. Simulation results showed that under the conditions of considered cutting area average productivity of forwarder is slightly higher than possible performance of the harvester under given conditions, which leads to forced outages of forwarder, which account for about 12% of time. When modeling, distribution of forwarder' down time and allocation of its working time on the transaction is given. As a result of performed study it was recommended to replace forwarder Komatsu 890.3 by more light and economical forwarder Komatsu 860.4. Simulation performed after making the model changes, showed that in this case forwarder's down time is reduced from 12% to 8%. Taking into account lower costs of buying and maintenance of this forwarder, as well as lower fuel consumption, it was determined that in the case of proposed option, it will possible to reduce the specific costs for procurement of one cubic meter of wood 274.7 to 266.7 RUB, i.e. by 3.1%. Thus, in solution of real industrial problem, the effectiveness of the proposed approach to the assessment of options for the acquisition of systems of machines for wood harvesting has been proven.