Modern Research in Decision Making

Abstract Decision making in the real world requires considering the evidence and information obtained from various sources that are effective in decision making, sometimes this evidence and information is available and accurate and sometimes so complex and ambiguous that it leads to the emergence of decision styles. There is a lot of confusion. The present study seeks to provide a model for determining managers' decision-making style, especially in the context of data uncertainty, by using probability laws based on data reliability and based on mathematical theory. Improve decision-making effectiveness In this model, the decision was made based on its quadruple component according to the opinion of the reporters, and based on the theoretical model of modeling evidence and nonlinear model. Then, a questionnaire containing 18 questions about the type of problem ahead was distributed for decision making in the managers of the branches of one of the private banks in Gilan province and based on the Likert spectrum. The obtained data were obtained by modeling the presented model and the final results. The results showed that in case of data certainty, analytical and rational approach and in case of data uncertainty, intuitive approaches are used for decision making. In addition, the proposed model provides a solution for obtaining and improving the effectiveness of decisions by consolidating the opinions of experts.

Abstract Raw materials supply costs form more than 60 percent of the price of a product in an organization. Therefore, the raw material supply planning has considerable effect in reducing the cost. Supplier management is one of the most important parts in supply chain management. Most of firms have been spending considerable amount of their revenues on purchasing. Hence supplier selection is one of the most important functions of purchasing management. The aim of this research is providing a linear integer mathematical model for supplier selection and order allocation with shortage and solving the model with three dimensional Fordyce–Webster Algorithm. In this research for the first time, maximum once period backorder cost is added to the three dimensional Fordyce–Webster Algorithm. In order to measuring performance of the proposed model, a high-voltage switches company's data and data from two other examples have been applied to the proposed model and the model has been studied in terms of " changing the ratio of holding cost and backorder cost" and " number of suppliers and number of time period". Finally, to solve the model, maximum once period backorder cost is added to the three dimensional Fordyce–Webster Algorithm.

Abstract Considering the problem of funding start-ups because of their nature, some entrepreneurs developed crowdfunding in which funding is done via the Internet and social network instead of traditional methods. Crowdfunding is a complicated and dynamic phenomenon due to the fact that it has many models with distinctive characteristics, numerous stakeholders with different intentions, interdisciplinary nature, and differences in various countries due to diverse cultural, social, economic and technological conditions of such countries. In addition, studies conducted on this method are not significant in number and they have been conducted in an exploratory and partial manner so as to offer a preliminary understanding. As a result, it is necessary to adopt an approach capable of understanding complex-dynamic phenomena so as to be able to explain crowdfunding. The present paper designs a system dynamics model of crowdfunding for support of new Iranian knowledge-based IT start-ups so as to highlight the complexities and dynamics of the method. The sources for the development of the model include relevant literature (document model building), public opinions (crowd model building) and experts’ viewpoints (group model building). The results of model simulation suggest that the revenue of the platforms in their expansion, the existence of monitoring mechanisms, evaluation, and screening in the platforms have a significant effect on increasing the attraction of investors and capital, but activity in social networks is not very effective.

Abstract Isfahan is one of the Iranian metropolises, although it has long been regarded as the pioneer city of waste management in the country, it still processes and disposes Municipal Solid Wastes (MSW) using a landfill-based disposal system. Therefore, the Isfahan Waste Management Organization, by developing a program titled "Isfahan 1400 a city without Waste Landfilling", is attempting to gradually transform the current system into a modern system based on the production of energy and valuable materials from the wastes. This study is aimed at simulating the Isfahan’s waste disposal system using System Dynamics (SD) approach to determine the best way of eliminating urban wastes considering the financial and environmental perspectives. Key variables of this model are MSW generation rate, the total emissions of greenhouse gases, and the total profits, plus management strategies such as recycling, composting and landfilling. After simulating and validating the model, various solutions, such as “anaerobic digestion facility establishment", “reformation of waste processing lines”, and "RDF production line installment" are tested in the system and the best option is introduced. The simulation results indicate that implementation of each policy improves at least one of financial and environmental situations. Among them sequential implementation of "anaerobic digestion facility establishment" and "RDF production line installment" is designated as the best case.

Abstract Pricing and inventory strategies are two important decisions of a retailer which directly affect her/his profitability. They are even more prominent when the considered product undergoes deterioration. In this paper, the problem of joint pricing and inventory control is investigated in a competitive environment. In particular, we consider a number of competing retailers who sell substitutable deteriorating items to a common market. In addition, shortage is allowed and partially backlogged at the retailers. Each retailer aims to maximize their profit determining their price and inventory policies. At first, the profit function of the retailers is derived. Then, the existence of Nash Equilibrium solution is shown. Next, a solution procedure is developed to obtain the equilibrium quantities of price and replenishment policy. Furthermore, a numerical study is carried out to analyze the effect of the main parameters on the equilibrium solution. Numerical results show that the increase of competition intensity would decrease the summation of the retailers' profits, while it would increase the total satisfied demands. Moreover, in contrast to the monopoly models, changing the deterioration rate at a retailer does not significantly impact his/her selling price.

Abstract Organizations with integrated production and routing programs sometimes encounter traffic when they use vehicles for distribution. So there are risks such as an accident that could result in damage, loss of product quality, unavoidable delivery delays, or even irreversible impacts on costs and service time. Therefore, by taking account the risk of accident into the production routing problem, the model becomes closer to reality. In this study, a production routing problem with the purpose of reducing costs and the risk of accident in the transportation with outsourcing, multi-product and multi-period, is considered in which the production routing problem combines with the lot sizing and vehicle routing problem according the supplier's inventory management system. Since this is an NP-hard problem, after modeling the problem, to solve it, a Non-dominated Sorting Genetic Algorithm II (NSGA II) has been used. To examine the efficiency of the algorithm, the solutions of ε-constraint method in GAMS obtained in small-size instances have been compared with NSGA II. Finally, to validate the proposed algorithm and evaluate its performance in large-size instances, the results of NSGA II have been compared with multi-objective genetic algorithm using several indices. The obtained results showed that the NSGA II algorithm had better performance.

Abstract The COVID-19 Crisis, by showing the boundary states of socio-economic systems, has affected various areas of human life and has challenged many growing trends in trade and industry. . Participatory decision-making is one of the most important of these areas. This study seeks to examine the effects of the COVID-19 Crisis on different layers of participatory decision-making knowledge, and to estimate the necessary changes in participatory decision-making for life in the post COVID-19 period. Therefore, it is an essential step in organizing post-crisis participatory decision-making. Accordingly, using the Fundamentalism Strategy, the effects of the Corona Crisis on participatory decision-making at the three levels of principles, theories and techniques have been studied and analyzed. The results show that participatory decision-making at each of the introduced levels is affected by the Corona crisis. Also, at all levels, there has been areas of decision-making that remain completely unchanged. Further analysis shows that, despite the quantitative view, the most important effects have been created at the level of participatory decision-making principles and philosophical theories. The results of this study indicate the need for paradigm shifts in participatory decision-making in the post COVID-19 period. Finally, this study provide suggestions for further research and empirical suggestions.