چكيده به لاتين
Today, given the expansion of knowledge, the acceleration of the global economy, and changes in consumer preferences and tastes, considering the competition and competitors' reactions is one of the most critical factors for success in the global community. Fierce competition in today's markets has forced organizations to act as members of the chain. The activities of different sectors in each organization play an important role in the chain performance and its competitiveness in the form of a supply chain network and material flow management through this structure. Designing an efficient network to develop a supply chain structure, and integrate all its activities, plays a key role in the successful performance of the chain and increasing its competitiveness. Considering competitive factors is one of the most important reasons for the survival of any supply chain in the market. Price is one of the main competitive factors. Deciding on the optimal price has always been the most crucial issue in the supply chain, especially in today's competitive environment. Moreover, the concept of sustainable development has been the focus of organizations due to the existence of environmental laws, the impact of organizations on society as well as economic survival.
The present study aims to investigate the closed-loop supply chain network design problem for perishable products considering competition and uncertainty. Proper decision-making about the network structure of perishable products is critical due to their short lifespan, as the storage constraint in production systems is a major challenge for maintaining such products. Planning for perishable products requires a time-consuming and complicated process, taking into account the goals of increasing sales, maximizing profits, and achieving customer satisfaction. In this study, it is assumed that a new chain enters the competitive environment of the perishable product market and competes with the existing competitor in the market for the price. In this study, the modeling process is performed in two stages. The first stage deals with the supply chain network design of dairy products. At this stage, a three-objective sustainable optimization model is presented with the objective functions of minimizing total costs, minimizing adverse environmental effects, and maximizing positive social effects. Then, in the second stage, the new chain competes with the existing chain to determine the optimal price, which is modeled using two simultaneous competition and Stackelberg competition models. In this study, the multi-objective model is converted to a single-objective model using the constraint method. Due to the uncertainty in parameters of demand and capacity of facilities, the robust possibilistic programming approach is employed. The results of solving the model are obtained using real data of the dairy industry in Tehran by GAMS software. Finally, the sensitivity of important parameters is analyzed, and the comparison of the two mentioned competing approaches are discussed. The results show that supply chain facilities are constructed in places where a balance is struck between the three objective functions of sustainability. Also, the results of the competitive model indicate that since the existing chain is already active in the market and has a higher utility to attract customers, with the entry of the new supply chain into the market, the profit and the product prices of the existing supply chain will be higher.
