Effects of different cut-to-length harvesting structures on the economic value of a wood procurement planning problem

In this paper, we develop a Mixed Integer Linear model for a practical multi-facility wood procurement-planning problem using a cut-to-length (CTL) bucking system. This forest management problem is difficult to solve since it integrates the forest bucking problem and the multi-facility supply planning problem. A priority list approach was used to generate adequate bucking patterns for the Eastern Canadian context of operations. The model proposes a decision support with respect to: how to harvest the different cut blocks according to the bucking priority list used, and in what quantities harvested logs should be transported to saw mills. It aims at minimizing a combined non-linear harvesting cost, a transportation cost, an inventory cost and the maximization of the products value (i.e., profit maximization). The harvesting cost, used in the model, considers the non-linearity of the harvester productivity function, which is an important aspect of the decision-making process in current forest management. The model was used to compare the current bucking scenario to two new conceived ones. These scenarios allow investigating the gains and losses that could arise from the use of different bucking aggregations. More specifically, they consider the disaggregation impact on the number of different log types per block and so on its associated harvesting cost. Moreover, they aim to better understand the cost/benefit trade-off of implementing a more complex decision structure in a Canadian wood procurement context. In tests and comparisons between the scenarios, A. DEMS École polytechnique de Montréal E-mail: [email protected] L.M.ROUSSEAU École polytechnique de Montréal E-mail: [email protected] J.M.Frayret École polytechnique de Montréal E-mail: [email protected]