ماهان صادقي

Supply chains in various industries strive to create a competitive advantage over their rivals by adopting environmentally friendly solutions an‎d reducing costs. In the dairy industry, which faces dynamic customer deman‎ds an‎d high sensitivity of products due to their perishable nature, designing a flexible an‎d efficient supply chain to mitigate risks becomes particularly important. One of the most significant risks is disruptions caused by epidemics, the effects of which have been observed following the outbreak of COVID-19. Such disruptions can disturb the normal functioning of various levels of the supply chain an‎d impose substantial costs on the system. This research presents a mathematical model for designing a closed-loop supply chain network that considers the risk of epidemic disruptions under uncertainty. The perishability an‎d short lifespan of dairy products, which increase the risk of waste, are also taken into account in the proposed model. The closed-loop supply chain network can help reduce operational costs, optimize resource utilization, an‎d minimize waste, leading to lower overall supply chain costs. The network under consideration is multi-period an‎d multi-product, with decision variables including the flow of materials between levels, the inventory levels at each facility in each period, an‎d the selec‎tion of transportation modes for movement between levels. The model has two conflicting objectives: minimizing costs an‎d negative environmental impacts. The source of disruption, which is epidemic diseases, affects collection centers, leading to a significant loss of their capacity. To counteract this, a backup collection center is utilized as a resilience strategy. Additionally, considering the uncertain deman‎d, the problem is modeled using a robust stochastic programming approach based on scenarios, an‎d the bi-objective problem is solved using the epsilon-constraint method. The dairy industry in the 22 districts of Tehran is also considered a case study, an‎d the results from solving the model using real data in the GAMS software are presented. A sensitivity analysis was conducted on key parameters, revealing that the objective functions increase with rising deman‎d. Moreover, the implementation of the resilience strategy, despite increasing the economic an‎d environmental objective functions, prevents disruptions to the supply chainʹs operation.

زنجيره تأمين حلقه‌بسته , اختلال اپيدميك , تاب‌آوري , شبكه پشتيبان , بهينه‌سازي استوار

Closed-loop Supply Chain , Epidemic Disruption , Resilience , Backup Network , robust optimization

Sadeghi

Dr. Jabal