A system dynamics model for green logistics in a supply chain of multiple suppliers, retailers and markets

This paper aims at developing a system dynamics (SD) model to analyse the effect of green transportation and logistics on the total transportation cost of forward supply chain (FSC) and the total amount of CO2 emissions. The proposed green forward supply chain (GFSC) model considers multi-suppliers, retailers and markets, two types of suppliers (quick response and slow response), a single manufacturer, three retailers, and three markets. Based on SD model, the performance of GFSC was measured by CO2 emissions and total transportation costs for two transportation modes; regular (fuel) and hybrid trucks. Based on simulation results, the retailer that contributed to largest transportation costs and CO2 emissions was identified. Alternative green transport scenarios were proposed and then evaluated. Furthermore, a comparison between the performance of existing and suggested scenarios was conducted. Finally, sensitivity analysis was conducted to assess the impacts of model variables; CO2 factor and fuel consumption. The results showed that the use of regular trucks resulted in large transportation costs and CO2 emissions in FSC. In conclusion, planning engineers can utilise the proposed GFSC model in determining transport solutions that achieve green logistics system, cost-efficient supplier selection, and measuring performance of GFSC.