چكيده به لاتين
Regarding to mass production of raw milk in the country and the production of numerous dairy products, studying the supply chain of dairy products can be effective on the efficiency of this process in the country. The special conditions for the production, storage and distribution of dairy products are due to the characteristics related to spoilage, limited shelf life and the importance of freshness of these products. The variety and high number of dairy products, the limited shelf life and the importance of the freshness of these products on the sales show the complexity of decision making for the dairy supply chain network managers. On the other hand, the uncertainty in demand parameter which is one of the most influential parameters in decision making has added to the complexity of network management. Therefore, in this thesis, we consider the supply chain network design of dairy products with the limited shelf life and freshness of the products under uncertainty demand. The network under study is multi product, and multi period. This thesis presents a deterministic model and two non-deterministic models. The mathematical model is a single-objective mixed integer linear programing model.
The freshness feature is obviously very important to consumers of dairy products. So the customer is looking for the fresh product. In other words, the inventory system in retailers level is “Last Expired First Out” (LEFO). Therefore, this thesis attempts this system to the model. One of the innovations of this thesis is the modeling of the LEFO system for dairy retailers. multi-stage stochastic programming is used to deal with uncertainties in the demand parameter. A new robust optimization is presented. The robust optimization method presented in this thesis is introduced for the first time in the literature. Finally, the results of numerical example solution and case study of Tehran dairy network were investigated and the performance of multi-stage stochastic programming and robust optimization methods was investigated and the presented robust optimization model was shown to be successful. On the other hand, the necessity of considering the LEFO system at the retailer has also been examined, and it has been shown that incorporating this approach into dairy product consumers will increase costs and ignoring it causes avoiding optimal decisions.