Morteza Khorram; Mahmood Eghtesadifard; Sadegh Niroomand
Abstract
This paper focuses on a novel model of the U-shaped assembly line balancing problem, in which the objective functions include cost, capacity, and quality are simultaneously examined. It is assumed that each task requires a set of equipment. In addition, the quality of tasks performed by each worker varies. ...
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This paper focuses on a novel model of the U-shaped assembly line balancing problem, in which the objective functions include cost, capacity, and quality are simultaneously examined. It is assumed that each task requires a set of equipment. In addition, the quality of tasks performed by each worker varies. Hence, the purpose of the model is that the total cost of the equipment is minimized and the quality of the work is maximized. Additionally, the number of workstations is minimized. To this end first, a multi-objective non-linear mixed-integer programming model is provided. Then, the model is linearized, and simulated annealing (SA) algorithm and two of its modified modes have been proposed to solve the problem. The proposed algorithm includes a new encoding/decoding scheme, as well as a local search for assigning the worker to each station. To determine the parameters in three algorithms, the experimental design has been used and various modes have been created by combining the parameters. Moreover, numerical examples were established based on the graphs found in the literature and the solution is compared with three algorithms, revealing the efficiency of each algorithm. Additionally, a case study on the nozzle assembly line in oil refineries was conducted to evaluate the efficiency of the proposed model and algorithm. Results from the case study show that the modified SA algorithms performed better.
Mohsen Jami; Hamidreza Izadbakhsh; Alireza Arshadi Khamseh
Abstract
In the management of the blood supply chain network, the existence of a coherent and accurate program can help increase the efficiency and effectiveness of the network. This research presents an integrated mathematical model to minimize network costs and blood delivery time in crisis conditions. In the ...
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In the management of the blood supply chain network, the existence of a coherent and accurate program can help increase the efficiency and effectiveness of the network. This research presents an integrated mathematical model to minimize network costs and blood delivery time in crisis conditions. In the present model, to ensure timely and sufficient blood supply, especially in crisis conditions, the new approach concentration of blood collection, processing, and distribution sites in the facilities, emergency transportation, pollution, route traffic (delivery delay), blood type substitution, and supporter facilities were used. Moreover, other important decisions, including locating all permanent and temporary facilities at three blood collection, processing, and distribution sites, and blood shortage, were also applied in the model. The proposed model was solved for several problems using the Augmented epsilon-constraint method. The results showed that deploying advanced processing equipment in field hospitals, the concentration of sites in facilities, and blood type substitution have significantly improved network efficiency. Therefore, managers and decision-makers can use the proposed approaches to optimize the blood supply chain network to minimize network costs and blood delivery time.
project management
Yahya Dorfeshan; Seyed Meysam Mousavi; Behnam Vahdani
Abstract
Critical path method is one of the most widely used approaches in planning and project control. Time is considered a determinative criterion for the critical path. But it seems necessary to regard other criteria in addition to time. Besides time criterion, effective criteria such as quality, cost, risk ...
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Critical path method is one of the most widely used approaches in planning and project control. Time is considered a determinative criterion for the critical path. But it seems necessary to regard other criteria in addition to time. Besides time criterion, effective criteria such as quality, cost, risk and safety are considered in this paper. Then, the developed problem is solved as a multi-attribute decision making problem by a new extension of MULTIMOORA method. Moreover, type-2 fuzzy sets are utilized for considering uncertainties. Type-2 fuzzy sets are more flexible and capable than type-1 fuzzy sets in reflecting uncertainties. Eventually, SWARA method is developed for determining the weights of efficient criteria such as time, cost, quality, risk and safety under type-2 fuzzy environment. Finally, an applied example has been solved to illustrate the calculations and the ability of the proposed approach. Based on the example, it is clear that the longest path in terms of time criterion is not a critical path, and other influential criteria are involved in determining the critical path.
Mohamad javad Ershadi; Amir Azizi; Majid Mohajeri
Abstract
One of the major challenges in the automotive industry is facing different risks, especially when new products are offered due to meeting the needs of customers, which leads to a lack of accurate identification in changing methods and design, new machinery and materials, demand, production speed ,and ...
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One of the major challenges in the automotive industry is facing different risks, especially when new products are offered due to meeting the needs of customers, which leads to a lack of accurate identification in changing methods and design, new machinery and materials, demand, production speed ,and so on. These can cause serious injuries and risks. To recognizing these risks, you need to look for the right ways to identify risks and prioritize them to exercise control over critical risks. Therefore, in this paper, after identifying the main areas of identified risks, production line risks were graded and based on that, the fuzzy cognitive maps approach was developed and 13 risks were identified in three groups of technical, strategic and operational risks were analyzed. Then, using interpretive structural modeling approach, the correlation of risks was evaluated and the most important risks were identified using the network analysis process. Finally, the results show that the risks of design errors, low motivation, lack of financial resources, lack of parts and low productivity are among the five main risks in the Isaco auto parts supply chain.
Farhad Etebari; Hasan Rabiee
Abstract
In recent years, considering perishable products in the cold supply chain, necessity of using alternative fuels in the distribution organizations vehicles and minimizing fuel consumption have great importance for designing distribution networks. The most important question in the distribution networks ...
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In recent years, considering perishable products in the cold supply chain, necessity of using alternative fuels in the distribution organizations vehicles and minimizing fuel consumption have great importance for designing distribution networks. The most important question in the distribution networks are locating depots and designing the most suitable routes for serving customers which are considered in the location-routing models. In this research, a location –routing problem model for a multi-product perishable food products distribution network in the cold supply chain with ability of refueling vehicles at fuel stations has been studied. As the issue relates to a fuel consumption model as variable and dependent on the loaded between vertices and in terms of product corruption in the distribution process by utilizing an unusual fuel fleet to reduce carbon dioxide production, an integer linear programming model has been formulated. The models are validated by numerical solution in GAMS software and due to complexity of the problem in the medium and large dimensions, metaheuristic algorithm has been tested to solve problems of real size with acceptable computational time and its efficiency.
Ali Akbar Mohamadian; Masoud Simkhah
Abstract
Supplier selection is one of the most important problems in management and optimization area which aims at optimizing cost of supply, quality of products and services, risk of non-supply etc. In the literature, risk of non-supply and brand effect on demand is not considered in the models. Inspiring of ...
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Supplier selection is one of the most important problems in management and optimization area which aims at optimizing cost of supply, quality of products and services, risk of non-supply etc. In the literature, risk of non-supply and brand effect on demand is not considered in the models. Inspiring of this fact, the current research develops supplier selection integer model to take lead time and risk of non-supply into account. To solve the model, LOKAD benchmark database are employed and a new adaptive variable neighborhood search will be introduced according to a scoring strategy to deal with complexity of the model and achieve optimal or appropriate near optimal solutions. According to Wilcoxon test, the obtained pareto solutions outperforms Luan et al. (2019) results. Sensitivity analysis of the solutions on budget reveals that the final profit is more sensitive comparing to lead time. In addition, distance from ideal and diversity measures used as quantitative measures to compare the results.
Azam Tariyan; Hessam ZandHessami; Abbas khamseh
Abstract
The construction industry has always had significant destructive effects on the environment. Using green supply chain management strategies to achieve sustainable construction is an effective approach to reduce environmental damage. Due to the vagueness of the dimensions, in this research, relying on ...
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The construction industry has always had significant destructive effects on the environment. Using green supply chain management strategies to achieve sustainable construction is an effective approach to reduce environmental damage. Due to the vagueness of the dimensions, in this research, relying on the qualitative approach and the interpretive paradigm and the seven-step meta-synthesis method, the effective components on the establishment of green supply chain management in the construction industry were explained. For this purpose, 728 related studies in the field of supply chain management, especially with sustainable, green, and reverse, were identified, reviewed, evaluated, and screened, and finally, based on the entry and exit protocol, 37 studies were coded in the research portfolio, which in total 73 primary codes were extracted and categorized into 13 concepts and 4 categories. Classification reliability was confirmed based on Kappa coefficient. The findings of the research showed that the components affecting the green supply chain management were identified based on four main categories including: the main factors of green supply chain management, facilitating factors, internal and external drivers and barriers, and finally, suggestions based on the extracted results From this research, it was presented to future researchers