Análise dos desvios operacionais na operação de corte com harvester : um estudo de caso na região Campos Gerais, Paraná, Brasil

Abstract

Resumo: A colheita de madeira mecanizada apresenta elevados custos operacionais e de produção e, para aumentar a produtividade e reduzir esses custos, são necessários estudos que facilitem a tomada de decisão da gestão. Nesse contexto, o objetivo deste trabalho foi levantar os desvios presentes nas operações de corte com harvesters, a fim de melhorar as técnicas operacionais adotadas pelos operadores. Para isso, o estudo foi conduzido em áreas operacionais de colheita de madeira de pinus sob corte raso aos 14 anos e eucalipto aos 7 anos, localizadas na região Campos Gerais, Paraná, Brasil. O sistema de colheita avaliado era o de toras curtas, sendo o corte realizado por harvesters das marcas Ponsse e John Deere com diferentes cabeçotes. Para a determinação dos desvios operacionais, realizou-se duas avaliações, sendo: T1 (tratamento 1 ou testemunha, ou seja, a operação de corte realizada pelos operadores sem tratativas, sento feita para diagnosticar onde os instrutores deveriam focar o treinamento), e; T2 (tratamento 2, ou seja, a operação realizada após as tratativas para medir os níveis de melhoria). Em cada avaliação determinou-se os tempos dos ciclos de corte de árvores individuais, considerando o início do ciclo o posicionamento do cabeçote na árvore até a abertura do cabeçote após a finalização do último traçamento. Cada ciclo operacional foi dividido em quatro etapas, sendo: (1) pegada de árvore; (2) corte (derrubada); (3) direcionamento de queda; e, (4) processamento. A amostragem foi constituída por 25 operadores; e, 50 avaliações no total, sendo duas avaliações para cada operador. Cada avaliação foi feita com trinta ciclos operacionais pré-estabelecidos para captar quatorze desvios operacionais. A análise estatística foi feita pelo método descritivo em que todos os operadores receberam tratativas. Assim, verificou-se que na primeira avaliação (T1) registrou-se um total de 403 desvios; enquanto que, na segunda avaliação (T2) foram 192 desvios. Portanto, houve uma redução média de 110% de desvios; uma redução do tempo para executar os ciclos, e, consequentemente, um acréscimo de 19% da produtividade efetiva. Portanto, recomenda-se que a metodologia das avaliações seja aplicada anualmente para direcionar os treinamentos de reciclagens dos operadores, para manter o bom nível operacional.

Mechanized wood harvesting has high operational and production costs, and therefore studies are needed to facilitate management decision-making to increase productivity and reduce these costs. In this context, the aim of this study was to identify the deviations present in cutting operations with harvesters in order to improve the operational techniques adopted by the operators. To do so, this study was conducted in operational pine wood harvesting areas under clear cutting at 14 years old and eucalyptus at 7 years old, located in the Campos Gerais region, Paraná, Brazil. The cut-to-length harvesting system, with Ponsse and John Deere harvesters with different heads, was evaluated. Two treatments were performed to determine the operational deviations, being: T1 (treatment 1 or control, meaning a cutting operation carried out by the operators without actions, which was done to diagnose where the instructors should focus the training); and T2 (treatment 2, which was the operation performed after the treatments to measure the improvement levels). Next, the cutting cycle times of individual trees were determined in each evaluation considering the head positioning in the tree as the beginning of the cycle until opening the head after completion of the last bucking. Each operational cycle was divided into four stages, namely: (1) tree marking; (2) cutting (felling); (3) fall direction; and (4) processing. Sampling consisted of 25 operators and 50 evaluations in total, being two evaluations for each operator. Each evaluation was made with 30 pre-established operational cycles to capture 14 operational deviations. Statistical analysis was performed using the descriptive method in which all operators received treatments. Thus, a total of 403 deviations was found in the first evaluation (T1); while 192 deviations were found in the second evaluation (T2). Therefore, there was an average reduction of 110% in deviations; a reduction in the time to execute the cycles, and consequently a 19% increase in effective productivity. Therefore, it is recommended that the evaluation methodology be applied annually to direct the operators’ continuous training to maintain good operational levels. Abstract: The Census of Agriculture periodically provides a portrait of the Brazilian rural environment including productive, social and economic characteristics. The present work aimed to perform an exploratory and quantitative analysis of the historical data series of Census of Agriculture in order to extract information about Brazilian silviculture, especially from 2006 to 2017. Despite the growth in area of the forest plantations in the last decade, mostly of eucalyptus and american pine, there has also been expansion of mahogany and teak plantations. The forest plantations, in 2017, were mostly present in large agricultural establishments with the legal condition of a corporation, directed by an administrator and non-family farming. It is observed that the silviculture activity is centralized, occurring in a few establishments in the municipalities, except for the Southern region, which presents a large diffusion of silviculture, since several establishments have forest plantations.