SUMMARY
In the present work a time study was conducted with the objective of adjusting equations to estimate the time of activities, productivity, operational costs and the production of the processor used in a harvest operation of stands of Eucalyptus grandis in plain topography in the state of Bahia, Brazil. The operational cycle of the processor consisted of the time spent to process a tree, and was divided in to stages, which were assessed using the methotodology of single activity times. The sampling unit was the operational cycle of the machine. The statistical analysis was based on regression analysis considering the selection procedure “stepwise”. With the adjusted equations it was possible to estimate the productivity of the machine taking into account the of tree diameter. Considering an operational efficiency of 70 % under the circumstances of the study, the productivity of the processor was 25,8 m3 cc/h, the operational costs 47,90 US$/h and the production costs 1,86 US$/m3 cc. On the basis of the obtained results it can be concluded that the time of tree processing has varied directly according to the diameter increase diameter; the preparation time, contrary to the processing time, only shows a weak correlation with tree diameter; productivity of the processor is directly proportional to tree diameter, when expressed in volume and inversely proportional when expressed in tree number; the costs per cubic meter of wood processed varies inversely with of increased diameter; from the operational costs, fixed costs had the highest proportion followed by the variable costs, administrative costs and costs for manpower; the production costs of the processor decreased exponentially with increasing tree diameter.
Key words:
mechanized harvest; productivity; costs; processor; Eucalyptus grandis