4 présentations

• 
  15h30 - 15h55

  Operational route planning integrating different value chains in horizontal collaboration

  • Asudeh Shahidi, prés., University Laval
  • Mikael Rönnqvist, University Laval
  • Nadia Lehoux , University Laval

  This research presents the integration of three biomass sectors to supply a mixture of feedstocks to a bioenergy plant in Quebec, Canada. Large-scale bioenergy production requires significant volumes of waste and residue resources, typically sourced from forestry residues, agricultural waste, and municipal solid waste. Since these feedstocks spread over large geographical areas, an efficient transportation planning becomes critical to gather and transport them to the energy plant, making these feedstocks economically attractive for bioenergy market. We propose a truck sharing strategy at the operational level to integrate forest, agriculture, and MSW sectors, as integrating truck planning over multiple value chains has the potential to significantly reduce transportation costs and improve the overall efficiency. This strategy shares the available fleet of trucks among the three sectors, where configurations are or can be compatible with the biomass type and include additional time for cleaning or re-configuration. We also propose a solution approach with two main phases to implement this strategy. First, a transportation problem formulated as a linear programming model is solved to establish the network connections, which are then used to enumerate all feasible routes for each truck. Second, an integer programming route-based model is solved to select the optimal routes for the trucks fleet. This approach is applied to a case study generated in Quebec with an average daily delivery of 70 full truckloads using 47 available trucks considering seven planning days. Results show that the routes found using the truck sharing strategy are 4.5% better than those found when each sector worked independently.

• 
  15h55 - 16h20

  Optimizing feedstock delivery in a pulp and paper mill: A Tactical model

  • Zahra Homayouni, prés., PhD candidate
  • Luc LeBel, Full professor
  • Nadia Lehoux, Full professor

  The pulp and paper sector relies on an efficient procurement process encompassing the harvesting, transportation, and delivery of wood supply to mills to maintain steady operations. However, various challenges influence the process efficiency, including fiber accessibility, transport capacity constraints, and supply uncertainty caused by suppliers’ diversity and fluctuating feedstock availability. Additionally, balancing different wood species (hardwood, softwood), ensuring fiber freshness, and handling multiple product forms further complicate the logistics. These challenges can disrupt production, and contribute to supply-demand mismatches, increasing costs and decreasing productivity. To tackle this problem, a Mixed-Integer Linear Programming (MILP) model was developed to propose a tactical procurement plan that minimizes the total cost for procurement operations while providing the specific mix of fiber demanded by the pulp and paper mill. The model also includes constraints such as capacity across supply, storage, processing, and transport as well as inventory target levels. The model is applied to a mill in eastern Canada. The case study demonstrates its practical applicability for a one-year planning horizon.
  Keywords: Wood Supply Chain; Pulp and Paper Industry; Procurement planning; tactical planning

• 
  16h20 - 16h45

  Flexibility in Transportation to Enhance Wood Delivery Precision

  • Niloofar Jahani, prés., PhD Candidate
  • Luc LeBel, Full Professor
  • Shuva Hari Gautam, Associate Professor
  • Vanessa Simard, Production planning and Optimization Supervisor in Domtar

  Performance of the wood procurement process can be evaluated based on the ability to deliver the precise product to the right customer at the right time and price. Wood procurement planning involves purchasing, harvesting, transportation, and storage decisions. It is influenced by changing weather patterns, dynamic forest inventory data, fluctuating market demand, and transport capacity limitations. These factors make it hard to synchronize raw material deliveries with sawmill production plans and customer orders. This study explores strategies to develop flexibility in transportation as a means to respond to fluctuations. Transportation plays a crucial role in bridging the gap between raw material supply and processing, directly impacting delivery reliability and cost efficiency. A Mixed Integer Linear Programming (MILP) model is developed to minimize related cost across a network of sawmills and transshipment yards. The model was implemented on a rolling planning horizon basis that evaluates fleet adaptability across four scenarios with varying degrees of flexibility: allowing both truck additions and removals, only adding, only removing, or making no adjustments. This model considers weekly periods over a horizon that includes of three seasons: accumulation, thawing, and equilibrium. Constraints such as transportation costs, limited storage, and geographical distribution are considered. The results demonstrate that incorporating dynamic fleet adjustments and transshipment yards leads to lower cost, can negate the impact of log supply fluctuations, and improves delivery precision.
  Keywords: Wood procurement; Wood supply chain; Wood flow management; Uncertainty; Transportation flexibility; Inventory

• 
  16h45 - 17h10

  Pathfinder – a tool for identifying best paths for automated forest regeneration machines

  • Mikael Rönnqvist, prés., Université Laval
  • Linnea Hansson, Forestry Research Institute of Sweden
  • Patrik Flisberg, Forestry Research Institute of Sweden
  • Anders Rowell, Forestry Research Institute of Sweden

  Effective forest regeneration is essential for sustainable forestry practices. In Sweden, mechanical site preparation and manual planting is the dominating method, but sourcing labour for the physically demanding work is difficult. An autonomous scarifying and planting system (Autoplant) could meet the requirements of the forest industry and, for this, a tool for regeneration planning and routing is needed. The tool, Pathfinder, plans the regeneration and routes based on the harvested production (hpr) files, soil moisture and parent material maps, no-go areas (for culture or nature conservation), digital elevation models (DEM), and machine data (e.g. working width, critical slope, time taken for different turn angles). The overall planting solution is either a set of capacity constrained routes or a continuous route and could be used for any planting machine as well as for traditional scarifiers as disc trenchers or mounders pulled by forwarders.
  Pathfinder was tested on eleven regeneration areas throughout Sweden, both with continuous routes and routes based on a carrying capacity of 1500 seedlings. The net operation area, species and seedling density suggestions were deemed relevant by expert judgement in the field. The routes provided by Pathfinder were compared with solutions given by two experienced drivers and a third solution based on the actual soil scarification at the site. Total driving distance did not differ significantly between the suggestions, but Pathfinder included less side-slope driving on steep slopes (≥27% or 15 degrees) and medium slopes (15-27%). The chosen threshold value for steep slopes (where side-slope driving should be avoided) affects the routing, and a lower threshold means more turning and longer driving distance.
  Pathfinder is not only a tool for routing of planting machines, but also helps in planning of traditional regeneration by providing a more correct net area and tree species suggestions based on the growth of the previous stand. It also diminishes the risk of severe soil disturbance by excluding the wettest area in the planning.