Inventory Routing Optimization for Empty Pesticide Container Collection in the Southwest of Buenos Aires Province

Abstract

This work proposes mixed-integer linear programming (MILP) models for the inventory management of Empty Pesticide Containers (EPCs) stored in Temporary Collection Centers (TCCs) located in the Southwest of Buenos Aires Province (SOB). The formulations also integrate routing decisions to Plastic Recycling Plants, determining collection routes for the TCCs over a multiperiod planning horizon. Since these operations rely on a heterogeneous fleet of vehicles that produce significant emissions, two alternative formulations are considered: one aimed at minimizing transportation costs and the other focused on reducing CO₂ emissions. In both cases, two collection constraints are evaluated: one requiring a minimum vehicle load at the end of each route, and another that also imposes a minimum total collection target for the system. Based on a known EPCs input profile, the proposed MILP models identify logistics alternatives that optimize container removal from the TCCs, defining efficient collection routes and frequencies for optimal inventory management. Additionally, the models select the most suitable vehicle type for each route from the available fleet, in order to reduce both costs and environmental impact. This tool enables the design of management strategies that minimize costs and extend the lifecycle of EPC material within the production system, thus supporting the transition toward a circular economy in the SOB agro-industrial sector.