supply chain management analyzing/modelling
Amin Farahbakhsh; Amirsaman Kheirkhah
Abstract
Purpose: The production routing problem is created by combining the two problems of lot sizing and vehicle routing. Previous research has examined the effectiveness of this combination in reducing costs. In this paper, the production routing problem is considered with the aim of minimizing the risk of ...
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Purpose: The production routing problem is created by combining the two problems of lot sizing and vehicle routing. Previous research has examined the effectiveness of this combination in reducing costs. In this paper, the production routing problem is considered with the aim of minimizing the risk of production and distribution of hazardous materials. Attention to social and environmental criteria related to sustainability is being increased by researchers today. Hazardous materials are harmful to human health and the environment. Accidents related to these materials often have far-reaching adverse consequences. Risk is a danger measurement criterion for operations related to these materials.Methodology: The problem is modeled as a mixed integer program. The risk function in the proposed model is nonlinear and depends on the load of the machine, the population risk, and the type of hazardous material. Given that solving the mathematical model with the nonlinear objective function is more difficult, this function is approximated by a piecewise linear function.Findings: In this research, 8 standard instances have been used to evaluate and solve the model and compare the two nonlinear and linear models. The results show that by using the approximate model, a better answer can be achieved at the same time. Through sensitivity analysis, the effect of changes to production capacity and warehouses on risk has also been looked into.Originality/Value: This research proposed the production routing problem for hazardous materials according to sustainability criteria using a nonlinear mathematical model and uses a piecewise linear approximation to solve the model.
supply chain management analyzing/modelling
Parisa Bolhasani; Mohammad Fallah; Reza Tavakkoli-Moghaddam; Akbar Alam Tabriz
Abstract
Purpose: Increasing the population, followed by increasing human needs and problems related to transportation, has led managers to seek for solutions by the goal of increasing economic profitability and reducing costs. Therefore, in this study, a set of location decisions, vehicle routing and inventory ...
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Purpose: Increasing the population, followed by increasing human needs and problems related to transportation, has led managers to seek for solutions by the goal of increasing economic profitability and reducing costs. Therefore, in this study, a set of location decisions, vehicle routing and inventory management has been used as the main tools to face with these problems.Methodology: model has been solved and validated by Gams software using Epsilon method in small scale. Since this is one of the NP-Hard problems, meta-heuristic algorithms, MOPSO, MOFF, MOIWO, NSGA-II have been used to solve large-scale problems.Finding: The results of all comparative criteria show the superiority of the MOIWO algorithm over other algorithms and the appropriate efficiency of these methods in solving the mathematical model, especially in high dimensions and short times.Originality / Value: In this study, the design of hazardous materials transportation network is considered by considering the decisions related to location, routing, inventory. For this purpose, a new multi-objective mathematical model with the objectives of minimizing cost, minimizing travel time and maximum social responsibility is presented. This mathematical model can be used in different areas and different dimensions.