SCRO / Journées de l'optimisation

HEC Montréal, 29-31 mai 2023


HEC Montréal, 29 — 31 mai 2023

Horaire Auteurs Mon horaire

FOM Forestry : Operations and management

29 mai 2023 10h30 – 12h10

Salle: TD Assurance Meloche Monnex (vert)

Présidée par Gregory Paradis

4 présentations

  • 10h30 - 10h55

    Optimization of harvest scheduling at the operational level

    • Rohit Arora, prés.,
    • Taraneh Sowlati, UBC

    Harvesting cost accounts for 35-50% of the delivered cost of logs. So, it is crucial to efficiently schedule harvesting activities to reduce the delivered cost of logs. In this work, a mixed-integer linear programming model is developed to optimize the scheduling of harvesting activities at the operational level, for a planning horizon of 12 weeks with weekly decisions. The unique aspects of the model are: 1) consideration of the precedence relationship between harvesting activities based on the slope of cut blocks, 2) movement of individual machines between cut blocks, 3) possibility of assigning multiple machines for each harvesting activity at each cut block, and 4) possibility of utilizing machines that can perform multi activity. The objective of the model is to minimize the total cost. The model determines the start time and the end time of operations of each machine at each cut block, the number of machines to be assigned for each harvesting activity at each cut block, the cut block that the machine should move to after completing its operation at a cut block, and the type of activity it should perform. The model is applied to a real case study of a forest company in British Columbia.

  • 10h55 - 11h20

    A decomposition method for log logistics planning at the operational level

    • Seyed Salar Ghotb, prés., UBC
    • Taraneh Sowlati, UBC

    Log logistics includes a variety of different activities such as sorting, transporting, and storing of logs. These activities account for a significant portion of the total log procurement costs. Thus, an efficient logistics planning leads to potential cost savings. This study introduces a decomposition approach for log logistics planning at the operational level incorporating practical aspects. In the first phase, a bi-objective mixed integer programming model is developed to determine daily flows of logs between supply and demand points considering a balanced workload, sorting decisions, compatibility requirements, and trucking contractors. The second phase, then, addresses the daily routing and scheduling of heterogeneous trucks through a mixed integer programming model considering overtime and synchronization of log loaders and trucks at both pickup and delivery locations. A simulated annealing algorithms is employed to solve the large-sized problem in a reasonable time, and the Taguchi method is used to tune the parameters of the algorithm. The proposed models and solution approach are applied to a real case of a forest company in British Columbia, Canada. Results indicate that workloads of contractors can be balanced by 0.4% increase in total costs. Also, assigning overtime to trucks reduces deadhead trips and generates cost savings.

  • 11h20 - 11h45

    Local forestry-based carbon solutions for Canadian mining operations

    • Kathleen Coupland, prés., UBC - Forestry
    • Gregory Paradis, UBC - Forestry FRM

    Globally, mining companies have taken initiatives to combat climate change by committing to carbon neutrality. Presently, current technology to reduce, mitigate or improve emissions from current operations are insufficient to reach this goal. Investment and exploration into nature-based carbon sequestration offers on method for companies to help reach carbon neutral, while potentially allowing mining companies to develop carbon credits to be sold on the expanding global carbon market. If mining operations were to examine the potential to fund carbon sequestration projects in forests surrounding current and legacy operation sites, they might be able to offset carbon emissions, improve community relationships and protect biodiversity.

    This research aims use a forest landscape optimization model (ws3) to explore the solution space when carbon sequestration is maximized while being constrained by biodiversity and even-flow timber supply. Additional, examination of wood product supply chains will be included, assuming that forest products can replace a proportion of the current carbon intensive materials. The goal is to show that managing forests for carbon sequestration and biodiversity will provide new opportunities for mining companies to invest in local nature-based carbon solution while providing benefits and opportunities to local communities.

  • 11h45 - 12h10

    Towards an open framework for optimizing source-to-sink forest system carbon flows

    • Gregory Paradis, prés., University of British Columbia

    Forest management can contribute to climate change mitigation through photosynthetic carbon capture, carbon storage in forest ecosystems and forest products, and substitution of high-carbon-intensity building materials and energy sources. A systems analysis modelling approach (i.e., tracking carbon from forests through forest products supply chains and then to product end-of-life) is key to accurately estimating net scenario-wise carbon emissions. Examples of systems-level model implementations in the literature are difficult or impossible to reproduce, as these experiments are almost all include one or more closed-source software modules and proprietary datasets. Furthermore, published implementations either use a sequential simulation approach to push scenarios through a multi-module modelling pipeline or only model part of the system. To address these shortcomings, we are developing an open software framework for optimizing source-to-sink forest ecosystem and forest products carbon stocks, fluxes, and displacement effects. We review system architecture and design, describe some open datasets we are developing as input for this framework, and show some preliminary results from ongoing case studies.