Carola Häggström

 Abstract

Although forest operations research has a more than 50-year-long tradition in the field of human factors, there is a current decline in resources put on continuous and systematic human factors research. Therefore, the overall aim of this thesis was to contribute new knowledge on working conditions in mechanized cut-to-length logging operations and their relationship to system performance. Findings from four different studies, each using different research methods and approaches, were compiled and discussed based on their relevance to operator working conditions and logging system performance in a Nordic context and with a broader international outlook.

A human, technology and organization (HTO) framework was used in Study I to scrutinize the problems that exist in the interactions between these three aspects. The body of knowledge on the H, T and O aspects was extended in Studies II, III and IV based on problem identification Study I.

In study II, it was emphasized that most Swedish logging contractors were relatively small enterprises working purely with machine operations. Consequently, with the exception of between harvester and forwarder, task rotation has limited potential to be implemented within most companies.

In Study III, forwarder crane work was essentially ruled out as a major source of harmful levels of whole body vibration (WBV). The results also indicated that the choice of grapple may prove important with respect to avoiding costly growth losses for the landowner and environmental concerns.

In Study IV, gaze behaviour was investigated in an observational field study. By comparing operators in first thinning, second thinning and final felling, a task-dependent information search pattern was identified. Specifically, the information on the bucking monitor and the tree being felled was less frequently attended to, i.e. less interesting, during first thinning than during the other operation types.

Taken as a whole, much of the forestry literature focuses on individual aspects of the work environment, as in studies II-IV, and a systems perspective is less frequently applied. A hindrance to applying a systems perspective is that it demands transdisciplinary research teams and interdisciplinary research. However, this should be seen as an opportunity and not a hindrance to successful future research. 

Read the doctoral thesis here.