Application of a primarily deductive framework describing time consumption for hauling of logs to road-side

Abstract

Forest management planning decisions are often based on the forest owner's goals, which typically focus on economic criteria. Logging operation work productivity functions are used when costing forest operations. These functions affect the conclusions drawn during forest management analyses because different logging environments give rise to different harvesting costs. When evaluating new combinations of machines and environments, there is generally a shortage of field data on productivity that can be examined in advance. We applied a previously published deductive framework describing time consumption in forwarding to known environments, in which field studies on forwarding have been conducted and for which extensive data are available. We then adapted the deductive framework to better reproduce the results obtained in the time studies. The deductive framework accurately reproduced the observed forwarding productivities; on average, the adaptation process improved the accuracy of this reproduction. However, it may also have reduced the accuracy of individual predictions. We conclude that the deductive framework can be used as a basis for constructing work productivity functions for forest management analyses, and can serve as a foundation when constructing new productivity functions based on time study results to use when pricing forwarding.

The multi-faceted Swedish Heureka forest decision support system: context, functionality, design, and 10 years experiences of its use

“…Costs for harvest operations are calculated with time consumption functions for harvesters and forwarders in thinning and final felling (Brunberg, 1995(Brunberg, , 1997(Brunberg, , 2004 as well as for harvesters and forwarders in forest fuel thinning operations (Sängstuvall et al, 2012(Sängstuvall et al, , 2014. The calculated operation times (depending on factors such as terrain, slope and stem density) are multiplied with an hourly cost for the machine type used.…”