Learn by doing: Modelling the effect of training and job interruptions on tree cutting time for chainsaw operators in plantation forests, Tanzania

Abstract

Timber harvesting in Tanzania uses semi-mechanized and labour – intensive logging systems. Manual or semi-mechanized logging operations by using hand tools are more favoured due to cheap labour availability. For example, tree cutting is done manually using two-man crosscut saws, axes or chainsaws. This study was conducted at Sokoine University of Agriculture Training Forest to assess the effect of training and job interruptions for chainsaw operators during tree cutting operations in softwood plantation forests in Tanzania. Tree cutting operations using experienced and inexperienced chainsaw operators were studied in three experiments; before training, after training and after the break. Time study and work sampling techniques were used for data collection. Descriptive statistics and modeling was performed for each crews’ performance. Results show that generally, experienced crew spends lesser time in cutting as compared to inexperienced crews. However, start up chainsaw crew spent 32% higher time for preparation before tree felling. However, the crew showed significant improvement after training unlike the experienced one. The analysis of the delay times start up crew was had a significant proportion of the delay times during the first engagement which decreased substantially in the other two experiments. Generally, there was an improvement of the cutting time after training for all crew categories with decrease after the break. This observation signifies that job interruptions impact the productivity of the crews. Therefore, on job training on resumption of the operations may significantly improve crews’ productivity, safety as well as ensuring product quality.

Key words: Tree cutting, training, chainsaws, time studies, Tanzania