Forwarding during final felling: work element-specific distributions of driving distances at the stand level

Automatic data collection is becoming increasingly common in cut-to-length forest operations. However, only few studies have analyzed automatically collected follow-up data from forwarders. In this study, we analyzed the driving distances of the four work elements <i>Driving empty, Loading drive, Driving loaded</i>, and <i>Unloading drive</i> (the sum of which being <i>Total driven distance</i>) of two forwarders operating in central Sweden. The analysis included finding the most appropriate probability density functions for each distance at the stand level (46 final felling stands in total, with one load as the unit of observation). The results showed that the mean intra-stand <i>Total driven distance</i> ranged 364–2393 m, and that most distances in the majority of the stands were positively skewed. Versatile probability distributions like <i>Generalized Extreme Value</i> and <i>Log-logistic</i> were the most common probability distributions. Our results provide researchers and managers a numeric understanding of the intra- and inter-stand variation of forwarding work. Hence, our study can help spread awareness of this variation to managers and foresters. With this awareness, managers, foresters, and researchers can better understand the pros and cons of follow-up data from forwarders, and how to best use and collect it. Our results can also be used by researchers as high-resolution indata during simulations of forwarding work. Additionally, the results can be used as a reference or control when determining the most suitable data distributions in future studies.