Influence of human factor on the time of work stages of harvesters and crane-equipped forwarders

Abstract

ABSTRACT:Harvester technologies represent the second most common logging system in the Czech Republic. The high productivity of this technology is very necessary to cover its acquisition and operational costs. A human factor -a machine operator is the most important factor that surely influences the machine productivity. That is why the aim of this study is as follows: to analyze the mutual dependence of machine operator's education and working experience and harvester and forwarder productivity. The analysis proves that the operator's education and even more his working experience are very important. The time of harvesting work stages was measured when the harvester was operated by an operator with two-year working experience and by an operator with no experience. The average time difference between the harvester operators was 64.9 seconds in one work stage. The statistical significance of different operation times was confirmed during technically demanding segments in the working stage (the boom out the felling head and tree processing). Operators with the same working experience in forestry mechanization -about 13 years but with different education carried out the haulage work stage. In this case, the statistical significance between calculated differences was not proved. This fact proves that the operator's working experience is more important than his education.

Operator's physical workload in simulated logging and timber bucking by harvester

“…The presented results reveal a difference in the physiological functions monitored in the course of individual studied work operations at the stage of timber harvesting simulated at a harvester simulator. A similar conclusion was made in preceding studies as well (Dvořák et al 2008(Dvořák et al , 2011. On the other hand, Fiľo (2010) determined muscle tension, unlike others, as a non-detection predictor for analyses of work performance in time.…”

“…Experimental measurements in operating and laboratory conditions have shown that the muscle tension in the individual muscle regions responds to given stimulations and that it changes not only as a result of the load of the locomotive system but also as a result of the person's mental condition (Dvořák et al 2008). In the case of a long-term physical workload the muscle regions are more strained, which results in decreased muscle performance and fatigue.…”

Productivity Standards for Harvesters and Processors in Italy

“…Some of these were difficult to introduce because their translation into suitable indicators would have required a subjective judgment by the researcher. This would be the typical case of such factors as working technique, operator proficiency, and operator experience, which do have a significant impact on productivity (Ovaskainen et al 2004, Dvořák et al 2008. Other variables were easier to record, and some of them were indeed recorded for at least part of the 38 origin studies.…”

Evaluation of Salvage Logging Productivity and Costs in Windthrown Norway Spruce-Dominated Forests

“…[29,31]). Numerous earlier forest work studies have been carried out to analyze the effect of the harvester operator on performance, and many studies have emphasized that there is a significant correlation between the work experience and skills of an operator and his/her productivity in forest machine work (e.g., [68][69][70][71][72][73][74][75]). For instance, Purfürst and Erler [74] have found out that together, the stem volume and the operator explain 84% of the total overall variation in cutting productivity, and the operator alone explains 37% of the variance.…”

“…Hence, on the basis of the results of this study, it can be concluded that a big leap has not necessarily been taken in the development of forest machine technology during the last ten years. Nevertheless, when comparing the results of different forest work studies, attention must be paid to the effect of the operator and his/her skills on his/her work performance in cutting operations [68][69][70][71][72][73][74][75]. As the influence of the harvester operator on the cutting productivity in windthrown areas is significant [29,31], it is very important that the skills of operators are superior for the purpose of cutting windfalls safety and effectively.…”