4 présentations

• 
  13h20 - 13h45

  Two-Echelon Capacitated Location-Routing Problem for the Organic Food Sector

  • Daniel Ocampo-Giraldo, prés., ESG-UQÀM
  • Ana María Anaya Arenas, ESG - UQAM
  • Janosch Ortmann, UQAM
  • Walid Klibi, CESIT

  In this presentation we introduce the Collaborative Location-Routing Problem for organic food distribution within a nonprofit organization that coordinates multiple producers and food banks to transport small, perishable shipments under strict service-level agreements. We propose two mixed-integer formulations: one using continuous-time synchronization and the other leveraging a time-expanded network. Both formulations capture key decisions on choosing transfer hubs, assigning vehicles, and respecting capacity and time constraints. Due to the complexity of these formulations, a tailored matheuristic is introduced. First, an interval-based network relaxation generates lower bounds by reducing time granularity. Next, feasibility checks identify valid transfers and routing schedules. Finally, a constructive heuristic refines routes and assigns commodities, yielding high-quality upper bounds within feasible computation times. Extensive experiments, based on real data from an organic food cluster, demonstrate the benefits of resource pooling and enabling intermediate transfers, resulting in reduced routing distances, fewer vehicle requirements, and stricter adherence to freshness constraints. Beyond efficiency gains, the framework supports more sustainable food logistics by lowering emissions and costs, particularly relevant for nonprofits and small producers. Overall, this approach highlights the value of synchronized, hub-based solutions in regional perishable supply chains.

• 
  13h45 - 14h10

  Optimizing Land Allocation in Mixed Circular Organic Farming

  • Hadi Gholizadeh, Universite Laval
  • Bahareh Mosadegh Sedghy, prés., University of Lethbridge
  • Mohammadreza Nematollahi, University of Saskatchewan
  • Alireza Tajbakhsh, University of Newbrunswick

  Abstract

  Context:
  Circular Agriculture (CA) and Organic Farming (OF) have become increasingly important in modern agricultural systems, focusing on sustainability, resource efficiency, and minimizing environmental impact. Manure management, in particular, represents a critical challenge in optimizing organic farming systems. Effective optimization strategies can not only improve farm profitability but also enhance environmental sustainability by minimizing waste and improving resource use. However, despite the growing relevance of optimization in agriculture, there remains a need for detailed, practical models that can guide decisions on resource allocation, especially when considering the unique constraints of organic farming.
  Objectives:
  This study aims to develop and implement an optimization model to analyze resource allocation in organic corn and beef production by a rancher-farmer operating within a circular agriculture (CA) framework. Specifically, the objectives are:
  1. To identify the optimal allocation of manure and other production inputs to maximize profitability while adhering to organic farming principles.
  2. To evaluate the impact of varying input cost factors and environmental constraints on the optimization process.
  3. To provide actionable recommendations for farmers and policymakers on improving resource efficiency within organic farming systems, particularly in the context of manure management.
  Methods:
  An analytical optimization model is designed, incorporating both economic and environmental variables that influence organic farming practices. The model accounts for the resource allocation decisions. Nine scenarios are investigated based on the excess or shortage of manure and corn as inputs in production of corn and beef respectively. A sensitivity analysis is conducted to evaluate how changes in key parameters—such as input costs and environmental policies, —affect the optimal solutions. This analysis allows for a deeper understanding of the factors influencing decision-making in organic farming. Afterwards, in the numerical analysis section, using real-world data we calculated optimal resource allocation in beef and corn production.

  Results:
  This study provides a nuanced and comprehensive analysis of organic agricultural production, focusing on optimizing resource allocation within a mixed crop-livestock organic farming system.
  Profitability and Resource Balance
  The highest profits were observed in scenarios where farms operated either with a surplus of at least one key resource (corn or manure) or with a simultaneous deficit in both. This finding suggests that maximum profit is not achieved through equilibrium but through strategic imbalance, which allows more efficient use or monetization of surplus resources and cost savings from reduced waste or storage.
  Surplus and Deficit Dynamics
  Scenarios with excess manure demonstrated higher profitability increase, when the willingness to pay for manure increased.
  Sensitivity Analysis
  The sensitivity analysis revealed that:
  • Higher selling weight positively influenced profit, while a higher initial weight had a negative impact due to increased purchase costs. Optimal profit occurs when lighter animals are purchased, and feeding is optimized for weight gain.
  • Subsidies: The effect of organic subsidy on profitability was most significant in balanced systems (equal consumption and production of corn or manure). In contrast, surplus-based systems displayed less sensitivity due to near-capacity operation and diminishing marginal returns.
  • Livestock Cost: Balanced scenarios demonstrate resilience to rising cow purchase costs, while profit-maximizing surplus scenarios were more vulnerable, indicating a trade-off between profitability and risk tolerance.
  Implications for Practice
  These results emphasize that optimal resource allocation in CA systems does not rely on balance alone but on strategic surplus and deficit management tailored to market dynamics and policy environments. For instance, surplus manure becomes a valuable asset under favorable WTP conditions, while targeted imbalances can improve efficiency and profitability. Furthermore, weight optimization and selective feeding strategies can significantly affect economic outcomes.
  The variation in sensitivity across scenarios illustrates the need for adaptive strategies in farm management and policymaking. A uniform subsidy scheme is insufficient; performance-based or scenario-specific incentives are recommended. Infrastructure support for storage, nutrient recycling technologies, and cross-farm resource exchanges could further enhance sustainability and economic outcomes.

• 
  14h10 - 14h35

  Meta-Heuristic Solution Algorithm for the Organic Food Collaborative Location and Routing Problem

  • Daniel Ocampo-Giraldo, prés., ESG-UQÀM
  • Ana María Anaya Arenas, ESG - UQAM
  • Janosch Ortmann, UQAM

  In this presentation, we introduce a meta-heuristic algorithm to solve the Collaborative Location-Routing Problem for organic food distribution. This problem arises in the context of a nonprofit organization that coordinates multiple producers and food banks to transport perishable goods under strict service-level agreements. We propose a multi-phase algorithm to determine the location of transshipment points (hubs) and the design of vehicle routes while minimizing the total cost.

  The first phase addresses the location and transshipment decisions. We propose an auxiliary mixed-integer programming model that approximates the routing cost and determines the number of hubs and the commodities transshipped at each hub location. The second phase takes the location decisions as input and generates a feasible solution using a greedy construction heuristic. Finally, we apply an adaptive large neighborhood search, adapted from the pickup-and-delivery problem with transshipments, to further refine the solution.

• 
  14h35 - 15h00

  Minimising food waste through harvest and side-stream valorisation - Optimisation for sustainable agri-food supply chains

  • Marloes Remijnse, Technical University of Eindhoven
  • Sonja Ursula Katharina Rohmer, prés., HEC Montréal
  • Ahmadreza Marandi, Technical University of Eindhoven
  • Tom van Woensel, Technical University of Eindhoven

  The potential of reuse and valorisation in order to reduce waste streams and recover resources in the chain is increasingly recognised. Despite this recognition, the potential of (edible) side streams, such as unharvested crop parts and vegetable peels, often remains overlooked and under utilised within the food and agricultural sector. This research develops a mixed-integer optimisation model to support decision-makers in determining an optimal product portfolio and processing configuration focused on side-stream valorisation strategies within food processing facilities. Considering both economic and environmental impacts, the model is solved for two key performance indicators, namely total profit and exergy loss. Examining potential trade-offs between these two objectives, the research is applied to a real-life case study from a carrot processing company and explores several scenarios and case settings to investigate the impact of various factors on the potential of side-stream valorisation. The findings from this analysis show that side-stream valorisation seems to be generally well aligned with profit maximisation, while it is not always beneficial from an environmental impact perspective.