A Carbon Aware Two-Echelon Location-Capacity-Routing Problem with Outsourced and In-House Delivery

The expansion of business operations has led to the widespread adoption of two-echelon supply chain structures across various sectors. Moreover, Green supply chain management has become increasingly important to reduce the environmental impacts of logistics activities. This study proposes a multi objectives mathematical model for the Green Two-Echelon Location Routing Problem, incorporating depot sizing decisions as part of the optimization process (2E-LCRP). The proposed model considers two objectives: (1) total cost, including cost of depot establishment, transportation, and vehicle usage across both echelons, and (2) total carbon emission, accounting for both transportation and depot operational emissions. Lexicographic optimization is employed to effectively balance these objectives. The model accommodates both outsourced and in-house delivery operations. Experimental results indicate that the proposed approach successfully manages the trade-of between cost and environmental impact. This work advances the field of green scheduling by providing a comprehensive framework for carbon emission assessment and extending the two-echelon location routing problem to integrate depot sizing decisions.