Modeling and Optimization of Daily Transportation Planning in Pulp Mill

This paper proposes a modeling and optimization strategy for the daily planning of wood transportation in the pulp and paper sector. The problem analyzed is formulated as Mixed Integer Linear Programming (MILP), with the objective of minimizing the variability of the basic density of the wood received by the mills, respecting fleet, crane and daily demand restrictions. The proposed optimization tool involves a mathematical heuristic based on the Variable Neighborhood Search (VNS) method and the Fix-and-Optimize technique, combining disturbance and local search steps to efficiently explore the solution space. The computer simulations were performed from a real instance and the results obtained suggest that the proposed heuristic was able to achieve adequate solutions in practical time, considerably less than the time required by a commercial solver. Thus, the approach shows promise for practical applications in large-scale production chains.