Design and Optimization of an Eco-Efficient Vehicle Routing Model for Heterogeneous Fleets and Multi Depot Systems

Abstract

In the dynamic landscape of vehicle routing problems (VRP), the traditional focus on cost minimization has significantly evolved due to the pressing need to address environmental concerns. With the logistics industry experiencing exponential growth and increased vehicle utilization, sustainability has become a central consideration both globally and in strategic planning. The Vehicle Routing Problem (VRP) remains a key challenge in logistics and transportation management, aiming to optimize routes and vehicle allocation to minimize transportation costs. This study introduces an innovative VRP model that intricately balances economic efficiency with ecological responsibility, addressing the urgent call for sustainable solutions amidst the ongoing environmental crisis. The proposed model features a diverse fleet of trucks, each designated for specific product types, creating a heterogeneous fleet. Originating from multiple depots, these trucks ensure comprehensive geographic coverage and enhance logistical efficiency. The core objective of the model is twofold: minimizing the financial transportation costs associated with supplying multiple products from multiple depots to customers and significantly reducing the carbon footprint, thereby addressing environmental sustainability. Two distinct solutions are proposed: one based on mixed-integer linear programming (MILP) and the other utilizing a heuristic approach. The choice of mixed-integer linear programming instead of linear programming is due to the need to make binary route decisions. Results are compared, focusing on outcome variation and computation time. Additionally, the solution demonstrates upto 100% variation in results when comparing the heuristic model with the optimal values derived from mixed-integer linear programming, though it requires less computation time. This research underscores the importance of seamlessly integrating economic and environmental considerations in the logistics industry. The proposed model embodies this principle, representing a substantial step towards a more sustainable future. By aligning objectives with global sustainability goals set by the United Nations in 2015, this research contributes to the discourse on sustainable development. It lays the foundation for future innovations in vehicle routing and logistics.