Mehdi Seifbarghy; Maryam Mohajeri
Abstract
This paper investigates a joint economic lot sizing model for a two echelon supply chain consisting of a single-vendor and multiple buyers. Recent studies have focused on the problem with equal batch sizes while this study proposed a mixed integer nonlinear programming model considering unequal batch ...
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This paper investigates a joint economic lot sizing model for a two echelon supply chain consisting of a single-vendor and multiple buyers. Recent studies have focused on the problem with equal batch sizes while this study proposed a mixed integer nonlinear programming model considering unequal batch sizes and shortage to minimize supply chain total cost. A heuristic procedure is proposed to find the solution and finally we show that unequal batch sizes delivers a more cost efficient solution.
Javad Behnamian; Amir Afsar
Abstract
In general, numerous studies have paid a special attention to machine planning, job allocating and job sequencing in scheduling problems to optimize makespan. Due to the relation among economy, energy and environmental concerns, energy use is one of the most important issues in different systems planning. ...
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In general, numerous studies have paid a special attention to machine planning, job allocating and job sequencing in scheduling problems to optimize makespan. Due to the relation among economy, energy and environmental concerns, energy use is one of the most important issues in different systems planning. In this paper, a scheduling of heterogeneous parallel machines is studied, in which the job process speed on every machine is settable. Since there is a direct link between used energy of machines and process speed, the purpose of the paper is to minimize total used energy and tardiness-related costs in delivering customers' demand. In order to optimizing the problem, two meta-heuristic algorithms, Memetic algorithm and Genetic algorithm, are developed, finally the results of both algorithms are analyzed and then compared to each other as well as to the results of the GAMS optimization software.
Laya Olfat; Maghsood Amiri; Iman Raeesi Vanani; Mansour Esmaeilzadeh
Abstract
Today, it is difficult for organizations to survive without improving supplier performance and supplier relationships or gain competitive advantage. Therefore, suppliers must be managed and developed to meet the needs of the producer company. On the other hand, the supplier's development requires the ...
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Today, it is difficult for organizations to survive without improving supplier performance and supplier relationships or gain competitive advantage. Therefore, suppliers must be managed and developed to meet the needs of the producer company. On the other hand, the supplier's development requires the introduction of precise and comprehensive criteria. The aim of this paper is to identify the dimensions and categories of supplier development based on the criteria related to it, using the Meta-synthesis method. For this purpose, first we selected 102 studies from 136 studies, coding their texts with Atlas TI software, 23 concepts were identified for the criteria. Subsequently, through the analysis of literature, the identified concepts were classified into four tangible, intangible, environmental, and external dimensions and internal dimensions. To verify validity, triangulation of data, sources and researcher has been used. The content validity ratio and content validity index were calculated by a survey of automobile industry experts, four of the criteria were directly eliminated, and modifications and modifications were made on the criteria, and finally, 17 criteria for the development of suppliers in the automotive industry were finalized. The amount of Kappa coefficient obtained shows the reliability of the identified criteria. Finally, a two-dimensional model is proposed for the supplier-development criteria. Due to the lack of categorization of the criteria related to the supplier's development in previous studies, and in particular in domestic research, the identified criteria and their categorization can be useful for researchers in this field.
alireza alinezhad; Abolfazl kazemi; Marzieh Karimi
Abstract
Location, routing and allocation decisions in supply chain management philosophy is undoubtedly one of the most important issues have very effect on the supply chain cost reduction and customer satisfaction. This paper presents an integrated approach to the distribution network. The objective functions ...
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Location, routing and allocation decisions in supply chain management philosophy is undoubtedly one of the most important issues have very effect on the supply chain cost reduction and customer satisfaction. This paper presents an integrated approach to the distribution network. The objective functions of the proposed mathematical model consist of minimizing the total costs associated with transportation and warehouse rental costs and also minimize the risk of the system. The model has high computational complexity and the exact method of solving it is not possible in a reasonable time. To solve the proposed model a multi-objective meta-heuristic algorithm which, known as the objective harmony search algorithm is presented. To demonstrate the effectiveness and efficiency of the proposed algorithm in solving the model, algorithm parameters are adjusted in the best possible rates using the Taguchi method. Then a random sample of the issues generated and the performance of the proposed algorithm comparing with NSGA-ǁ and NRGA are evaluated
Masoud Fazli; Ahmad GafarZadeh Afshari; Mostafa Hajiaghaei-Keshteli
Abstract
Green building has attracted widespread attention in recent years. Increasing building projects in Iran has had significant environmental impacts and green building implementation is an appropriate approach to reduce the environmental risks. Green building projects facing with risks unwittingly which, ...
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Green building has attracted widespread attention in recent years. Increasing building projects in Iran has had significant environmental impacts and green building implementation is an appropriate approach to reduce the environmental risks. Green building projects facing with risks unwittingly which, reduce their efficiency. Therefore, identifying and ranking the risks can play a significant role in the success of green building projects. Due to the few studies in this area in Iran, this study aims to provides a new comprehensive framework of all the criteria and risks of green building projects. For this purpose, the first step aims to identify and screen the risks from the viewpoint of experts in green building projects and introducing the risk assessment criteria. After that, the next step is to apply the SWARA method to obtain the weight of the criteria. Finally, Ranking of the risks of green building projects has been done using the COPRAS method. This is the first attempt to solve a green building project using a hybrid of SWARA and COPRAS through a case study (Amol). The results show that risks of: the low quality of materials and equipment, the stakeholder resistance to approve the green ideas and lack of realistic goals are very important. The proposed framework can help stakeholders of green building projects in developing countries to manage project risks more efficiently.
Akbar Moradi; Alireza Amirteimoori; Sohrab Kordrostami; Mohsen Vaez-Ghasemi
Abstract
Data Envelopment Analysis (DEA) is an estimator. This estimator tries to assess a relationship between multiple inputs and multiple outputs, and an identified technology. In traditional DEA models, firms are classified into two divisions, efficient and inefficient. Efficient firms are considered as a ...
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Data Envelopment Analysis (DEA) is an estimator. This estimator tries to assess a relationship between multiple inputs and multiple outputs, and an identified technology. In traditional DEA models, firms are classified into two divisions, efficient and inefficient. Efficient firms are considered as a reference for inefficient firms. In traditional DEA models, the efficiency improvement has been inspected for inefficient firms and efficient firms are assumed to be unchanged. Since the estimated technology is rationally smaller than the real technology or in other words, the estimated technology is always the subset of the true technology, we can expand it a little. Thus, we can improve efficient firms. This is done by creating some virtual DMUs. In this paper, an algorithm is proposed to expand the Production Possibility Set (PPS) and to improve efficient firms. To illustrate the proposed approach, numerical and applied examples are provided. The results are explained and discussed.
Neda Manavizadeh; soroush aghamohamadi-bosjin; Parisa Karimi-Ashtiani
Abstract
This paper proposes a bi-objective model for the waste collection problem and considers the location, routing and inventory of the system simultaneously. Considering the reverse flow of the system is another feature of the current study. In the proposed model, the total costs of the system are minimized. ...
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This paper proposes a bi-objective model for the waste collection problem and considers the location, routing and inventory of the system simultaneously. Considering the reverse flow of the system is another feature of the current study. In the proposed model, the total costs of the system are minimized. In addition, the related risks of opening new centers and transportaion are included as the second objective function of the problem. Considering the delivery time and cpacity of vehicels constraints, are the other features of the model. Due to the NP-hardness of the model, two metaheuristic algorithms namely a non dominated sort ordering genetic algorithm (NSGA-II) and a multi objective particle swarm optimization algorithm (MOPSO) are applied to solve the problem. According to the results, NSGA-II is able to reach better answers in all the propsed metrics. According to sesitivity analysis, foreign transportation fleets make a great impact on the costs of the system.
Ebrahim Alimohammadi As; Alireza Bafandeh Zendeh; Houshang Taghizadeh
Abstract
The study aims to simulate the strategies of Islamic Azad University (Tabriz branch) during 2019- 2034 period through system dynamics approach. Based on research literature, student trend, physical resources, educational quality, human resources, research and publication and financial operation were ...
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The study aims to simulate the strategies of Islamic Azad University (Tabriz branch) during 2019- 2034 period through system dynamics approach. Based on research literature, student trend, physical resources, educational quality, human resources, research and publication and financial operation were considered as key effective variables in formulating the strategies. By using reliable theories in the field of problem-solving literature and experts' opinion, causal relations between variables have defined in the form of mathematical functions and finally simulated has been done. The scenarios were formulated and analyzed based on three main objectives, namely cost reduction, increase of revenue and educational quality development. Results show that by the implementation of downsizing scenario in Tabriz Azad University, the tuition rate of the university experienced a decrease of five percent. The second scenario show that if research budget experiences a change of 40%, non-fee revenues would grow 19%. The simulation of the third scenario revealed that, 25% increment of new investments in Tabriz Azad University leads to the growth of student attraction rate by 17% in long term. By considering results of three scenarios we could suggest that Tabriz Azad University should follow the two strategies of increasing research budget and making use of new investments.
Seyed Mohammad Hasheminejad; Eehsan Mhammadian Amiri
Abstract
Nowadays, managers in the public and private sectors consider having knowledge of green laws and issues are essential in surviving of their organizations. Although researchers have promoted each issue of green human resource management and green supply chain management separately, but there has been ...
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Nowadays, managers in the public and private sectors consider having knowledge of green laws and issues are essential in surviving of their organizations. Although researchers have promoted each issue of green human resource management and green supply chain management separately, but there has been a great delay in integrating these two issues. Therefore, this study first attempts to provide an integrated and coherent framework for linking green human resource management and green supply chain management (GHRM-GSCM). For this purpose, firstly, using a comprehensive literature review of the research, interviews and expert opinion on the ornamental industry, the initial identification of evaluation indicators in green supply chain management and green human resources management was undertaken. In the next step, the causal relations were determined by using the fuzzy DEMATEL method and the weight of each of the criteria and sub-criteria were determined with the fuzzy ANP method. The results of this assessment show leadership, flexibility, and environmental factors based on their importance are identified as effective factors, and optimizing these factors by the Arya array industry could lead to other factors optimization (influencing factors).
Mehdi Yazdani
Abstract
This paper deals with the problem of two-stage assembly flow shop scheduling with considering sequence-independent setup times .The objective is to minimize totalcompletion times of all orders. In this problem, there are several orders for one type of product. Each ordered product is formed of several ...
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This paper deals with the problem of two-stage assembly flow shop scheduling with considering sequence-independent setup times .The objective is to minimize totalcompletion times of all orders. In this problem, there are several orders for one type of product. Each ordered product is formed of several different parts. At first, the parts are manufactured in a flow shop stage with some different machines and then they are assembled into a final product on a single machine. This paper presents three meta-heuristic algorithms, namely Parallel Variable Neighborhood Search (PVN) Artificial Immune Algorithm (AIA) and Simulated Annealing (SA), for solving under studied problem. The Taguchi experimental design method as an optimization technique is employed to tune different parameters and operators of presented algorithms. Also, Numerical experiments are used to evaluate the performance of the proposed algorithms. The results show that the PVNS algorithm performs better than the other algorithms
