Cable yarding productivity models: a systematic review over the period 2000–2011

The efficiency of cable-based yarding systems has been studied extensively, resulting in numerous work productivity models (i.e. models predicting the ratio between output and time). Productivity models are used in both research and operations management, but are laborious to develop. Efficient use of existing models is essential, but there is a lack of overviews of available models. Therefore, work productivity models developed in recent years were compiled, with the aim of increasing their visibility, accessibility and comparability to potential users and other interested parties. This compilation should facilitate comparisons and evaluations of the models and their influential parameters, and the synthesis of existing models. A systematic review of the international scientific literature on cable logging published between 2000 and 2011 was performed. Twenty-one publications describing productivity models were identified. These publications originated from four different continents, with most coming from Asia (specifically, Turkey). Many similarities were found between the models. For instance, more than half use yarding distance as an independent variable, whereas lateral yarding distance and load characteristics were used in only a third of the models. However, there were also many differences in terms of modeling praxis, model features, included parameters and the units used. Analysis of the compiled models suggests some potentially fruitful directions for future work in the field of cable logging productivity. More generally, model compilations such as that presented herein enable a range of analyses and harmonizations that benefit all kinds of forest operations