چكيده به لاتين
The delivery time of products, especially in industries like horticulture and fast foods, is of great importance. In these industries, products are sensitive to delivery times, and timely delivery can have a direct impact on customer satisfaction, operational costs, and even brand reputation. In such conditions, third-party logistics (3PL) providers play a very important role; they assist manufacturing companies in improving the product delivery process by offering services like inventory management, transportation, and order tracking. Moreover, one of the valuable concepts in supply chain management is the concept of supply chain sustainability; a sustainable supply chain not only reduces the wastage of resources and raw materials but also increases customer trust and improves relationships with suppliers. Therefore, emphasizing precise delivery timings within the framework of organizational environmental and social responsibility plays a significant role in organizing the supply chain and enhancing social and environmental values, which leading to benefits for manufacturing organizations from accurate delivery times and improving their competitiveness in dynamic markets. Thus, this research first examines a two-level supply chain consisting of a manufacturer and a retailer to consider all three dimensions of sustainability with the aim of coordinating the supply chain; in this model, the manufacturer decides on the level of greenness and the amount of donation of health products, and the retailer decides on the product's selling price. To coordinate the supply chain members, a combination of revenue-sharing and cost-sharing contracts is employed. In fact, this model aims to optimize pricing decisions, green performance, and social responsibility in a two-level sustainable supply chain. Subsequently, a three-level agricultural supply chain is examined to add the concept of product delivery time in the form of a second model, which includes a farmer, 3PL, and two retailers (online and offline stores). The 3PL ensures the delivery of products to customers before the freshness date and also packages the products using green methods. The farmer also performs humanitarian deeds through cash donations to charity. In this model, two distinct supply chain strategies are developed and compared. In the first scenario, the two retailers cooperate as a unified unit, while in the second scenario, the retailers compete with each other. According to numerical results, in the cooperative scenario of retailers and also in the competitive scenario, the 3PL and farmer earn more profit. Finally, the proposed third model, a new contract is developed based on the concept of delivery time, combining the optimal payment of the retailer to the 3PL for logistics activities, along with a franchise fee contract for coordinating a food supply chain, including the retailer and 3PL,. In this model, delivery time is modeled considering the shortest possible time for food product preparation and delivery under uncertain demand. Numerical results indicate the efficiency of the proposed contract and specify the effects of pricing strategy and optimal product delivery time on market demand and the profits of supply chain members. Sensitivity analysis on important parameters of all three models has been conducted, and the results are examined in the form of charts, providing a suitable analysis of each and so on.
