Mathematical modelling
Seyyed Mostafa Mousavi; Majid Motamedi; Rasoul Karimi
Abstract
A supply chain is a network that creates and delivers products and services to customers. In this research, the four-level supply chain in the field of food products, including the levels of supplier, customer, and central and secondary warehouses, has been investigated. A mixed integer mathematical ...
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A supply chain is a network that creates and delivers products and services to customers. In this research, the four-level supply chain in the field of food products, including the levels of supplier, customer, and central and secondary warehouses, has been investigated. A mixed integer mathematical model of the research problem is presented to minimize chain costs, including the setting up and preparation of warehouses, transportation between transfer levels, and holding products. The proposed model is developed based on constraints such as inventory, warehouse capacity, vehicle capacity, and multi-period multi-product. The decision variables are determined after solving the model, which includes the optimal number of central and secondary warehouses, the optimal amount of product transferred between the factory and central warehouse, the central warehouse and secondary warehouse, and the secondary warehouse and customer, the optimal amount of product storage in secondary warehouses, the type of vehicle for transportation between levels, and the capacity level of each product in each central warehouse. To validate the proposed model, experiments were conducted using the Kaleh company's real data in GAMS software. Finally, the sensitivity analysis of the model was carried out on two critical parameters influencing decision-making: demand and the cost of increasing the capacity of the central warehouse. The output results confirmed the validity and efficiency of the proposed model.
Case studies in industry and services
Seyed Alireza Hoseini Tabatabaei; Abdollah Naami; Alireza Rousta
Abstract
Economic researchers consider the development of transportation as blood circulation in the economic body of the country, which accelerating its circulation satisfies the vital and basic economic needs faster, and any kind of disorder and slowness in it causes great damage to the process of growth and ...
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Economic researchers consider the development of transportation as blood circulation in the economic body of the country, which accelerating its circulation satisfies the vital and basic economic needs faster, and any kind of disorder and slowness in it causes great damage to the process of growth and development. Therefore, some economists and planners have considered the economic growth to be dependent on the development of the transportation sector and the existence of enough vehicles and related facilities. In this regard, Iran is very important due to its special position near the borders of Central Asia and the Caucasus and because it’s a bridge between the two major continents of Asia and Europe and has access to open waters. The main problem of this research is to identify all the dimensions and components that affect the transportation (transit) of goods and products, and because we finally want to present a strategy, the next problem is to rank these factors and consider the most important components and dimensions of Islamic Republic transportation. Analytic hierarchical process was used to determine the importance and weight of the criteria and then Expert Choice software was used for ranking. Given that the subject of transportation is a specific and macro issue, investigating it from a marketing perspective is a novel perspective, the studies conducted by students have remained at the research level, and there have not been many related studies on marketing in Iran, the most important limitation of the research was the ability to explain the reason of conducting this research and controlling the interviews. The results of pairwise comparisons and weights are expressed in the following. Accordingly, among the 20 sub-criteria, the use of information technology is ranked first. After that, sustainable development and smart transportation ranked second and third, respectively.
