4 présentations

• 
  10h45 - 11h10

  Toward eco-efficiency while designing reverse logistics networks: The recycled wood case study

  • Julien Trochu, prés., ETS
  • Amin Chaabane, ETS
  • Mustapha Ouhimmou, ETS

  In this work, we present a reverse logistics network planning model that optimizes the wood recycling from the CRD industry. While aiming at maximizing the profit, our model also targets GHG emissions control and landfilling limitations to ensure the eco-efficiency of the recycling network.

  Reverse logistics, network design, optimization model, wood recycling, environmental considerations.
• 
  11h10 - 11h35

  A two-stage stochastic model for production planning in sawmills

  • Vanessa Simard, prés., Université Laval
  • Mikael Rönnqvist, Université Laval
  • Luc LeBel, Université Laval
  • Nadia Lehoux, Université Laval

  Sawmill activities are subject to supply uncertainty coming from uncontrollable forest yield. Because the availability of the resource is uncertain, the validity of production plans must be constantly verified to avoid stock shortage. We evaluate the potential improvement when using a multistage stochastic approach to plan production instead of a deterministic approach.

  Keywords: Stochastic optimization, yield uncertainty, forestry
• 
  11h35 - 12h00

  Analyzing the impact of implementing a logistics center for a complex forest network

  • François Sarrazin, prés., Université Laval
  • Luc Lebel, Université Laval
  • Nadia Lehoux, Université Laval

  This paper analyses the interaction of a forest logistics center with its surrounding network. A profit maximization model is proposed and applied to case study. Results show that a logistics center could add up to $ 0.90 in profits per cubic metre of wood available for harvest for the network.

  Key words: logistics centers, sorting yards, supply chain management and design.
• 
  12h00 - 12h25

  Network design of trails for harvesters and forwarders on harvest areas in order to reduce soil damage and improve efficiency

  • Mikael Rönnqvist, prés., Université Laval
  • Patrik Flisberg, Creative Optimization
  • Willén Erik, Forestry Research Institute of Sweden

  Avoiding soil damage after harvest and forwarding operations is very important. There are often contractual agreements to avoid damage and in the case it happens, there are often different forms of extra costs and penalties. In order to make a qualitative planning, there is a need of detailed information. The basic information is often provided by airborne laser scanning. This provides detail information on geometry, number of trees, their size and assortments. Another important aspect is so-called depth-to-water maps. The presence of water impacts the vulnerability of the soil against the machine systems. Information on the road system, location of round-wood piles, historical sites and areas selected for preservation is also necessary. With the information described, it is possible to make a pre-plan for the harvesters. However, it is also important to visit and inspect the harvest area in more detail. Often it turns out that some information is not correct and need to be revised. In order to make this re-planning onsite, it is necessary to have a system that can change this GIS information and to make re-optimization fast. In this presentation, we describe such a system developed for use in Sweden. Different versions have been tested and we describe the results and experiences using them at a set of harvest areas for two larger Swedish forest companies. The problem is a very large scale network design and we describe solution methods that guarantee fast solution times.

  Keywords: Network design, forestry, routing, large scale optimization