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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Journal of Industrial and Systems Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Corporate Social Responsibility,Supply Chain Coordination,promotional efforts,periodic review order-up-to policy,cost-sharing contract
- چکیده:
- چکیده انگلیسی: In this paper, we explore the issue of coordination in a manufacturer-retailer supply chain where the manufacturer is socially responsible and invests in CSR activities. On the other hand, the retailer invests in promotional efforts and uses a periodic review order-up-to policy for replenishing items. First, the decentralized decision-making structure is modeled to calculate the minimum acceptable level for the members profit to accept coordination. Then, the centralized structure is formulated to obtain the benchmark solutions for the whole supply chain profitability. Afterwards, a cost-sharing (CS) contract is proposed to persuade the members to accept the centralized decision-making structure and to follow the benchmark solutions. The results of the sensitivity analyses demonstrated that the proposed coordination model is beneficial from three aspects, i. e. economic, environmental and social viewpoint, compared to the decentralized model. Furthermore, some outstanding managerial insights are provided which further illustrates the applicability of the proposed model.
- انتشار مقاله: 10-10-1396
- نویسندگان: Seyyed-Mahdi Hosseini-Motlagh,Parvin Pazari,Mina Nouri
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Industrial and Systems Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Supply Chain Coordination,Pharmaceutical products,buy back contract
- چکیده:
- چکیده انگلیسی: Drug has a great and crucial role inboth the health systems and the quality of life, and thereforeits shortage can cause death.In order to the important role of drugs,pharmaceutical supply chain(PSC) shouldensure that drugs are delivered to people in the right time with the best quality.On the other hand, thesupply chain (SC) members depend on each other for resources and information, and it has increased in recent times due to outsourcing, globalization and rapid innovations in information technologies. This increase brings some extent of risk and uncertainty along with benefits for them and so, SC coordinationis a crucial issue. Thispaper studies a PSCmodel witha single active pharmaceutical ingredientsand a single finish pharmaceutical product. For this purpose, decentralized and centralized structures are investigated. Then,a coordination mechanism is developed based on the buyback contract in order to encouragethe SC members to make decision by considering each other's profit to simulate the condition of decentralized SC versus centralized one.In order to demonstrate the effect of the proposed coordination model, numerical examples and sensitivity analysis are provided. The results show that by applying buy back contract, in coordination structure the order amount of raw material and the profits of the pharmaceutical supply chain will increaseso it can effect on the amount of manufacturing orders.By using buy back contract, the profit of each SC member increasesin comparison with the decentralized decision-making structure.
- انتشار مقاله: 31-03-1396
- نویسندگان: Sayeh Foladi-Mahani,Saeed Yaghoubi,Seyyed-Mahdi Hosseini-Motlagh,Mohammadreza Nematollahi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Industrial and Systems Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Liner Shipping,Disruption management,Rescheduling,Transshipment,Fuel Costs,Container Demand
- چکیده:
- چکیده انگلیسی: This study presents a MILP model to retrieve or get close to the early schedule of disrupted container vessels. The model is appliedon a realcase study of Islamic Republic of Iran Shipping Lines (IRISL) considering container demands, and CO2 emissionssolvedwith CPLEX GAMS solver in less than a minute. Sensitivity analysis on fuel inventory level shows the inevitable influence of the fuel price and primary inventory level on ships costs. Variations in unavailability duration of the ships suggest that substantial changes in the objective function caused by omitting the port calls rather than speeding up the ships.
- انتشار مقاله: 08-05-1394
- نویسندگان: Sogol Saremi,Seyyed-Mahdi Hosseini-Motlagh,Seyed Jafar Sadjadi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Industrial and Systems Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Data mining,Bus scheduling,Dynamic Time Warping (DTW),Headway,AVL,K-means Algorithm
- چکیده:
- چکیده انگلیسی: The growth of AVL (Automatic Vehicle Location) systems leads to huge amount of data about different parts of bus fleet (buses, stations, passenger, etc.) which is very useful to improve bus fleet efficiency. In addition, by processing fleet and passengers’ historical data it is possible to detect passenger’s behavioral patterns in different parts of the day and to use it in order to improve fleet plans. In this research, a new approach is developed to use AVL data to investigate relationship between headway change and passenger downfall rate. For this purpose, a new method is developed that is called Intelligent Headway Selection (IHS) approach. The aim of this approach is finding similar days from passengers’ behavior perspective in the dataset and by focusing on unusual patterns of each group, headway changes effects on passenger downfall rate is being studied. In this approach, in the first step, each day is classified into specific time periods (like half of hours) and the passengers’ behavior pattern is detected for each day during the specified time periods. Then, in the K-Means algorithm, Euclidian distance measure is replaced with Dynamic Time Warping (DTW) algorithm to enable the K-Means to compare time series. The modified K-Means algorithm is used to compare days in the dataset and categorize similar days in the same clusters. Then, headway – passenger per minute plot is created for each time period to detect unusual patterns. Then, a Headway Interval Detection Procedure (HIDP) is developed to use these unusual patterns to find suitable headway values for each time period. Afterwards, these plots merged and the final headways are calculated.
- انتشار مقاله: 18-03-1394
- نویسندگان: Seyyed-Mahdi Hosseini-Motlagh,Peyman Ahadpour,Abdorrahman Haeri
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Hospital Research
- نوع مقاله: Journal Article
- کلمات کلیدی: Robust optimization,Disaster,Stochastic Modeling,blood supply chain,Emergency situations
- چکیده:
- چکیده انگلیسی: Background and Objectives: A sudden jump in blood demand during natural disasters may have strong negative impact on the performance of blood supply chain. Appropriate response to emergency situations requires predictive approach to determining the optimal allocation of blood supply chain resources for various disaster scenarios. The present study, thus, presents an optimization model aimed at decreasing blood shortage, blood wastage, and blood supply cost in emergency situations. Methods: This work is an extension of our previously introduced stochastic blood supply chain model, which was developed based on the Robust Optimization concept. The aim of this model is to determine the optimal number and service areas of the blood facilities under different disaster scenarios using mixed integer linear programming. While in our previous model, the capacity of blood facility center was assumed to be constant, in the present work, it is considered as an integer variable varying within a defined interval. The present model, hence, allows exploring the influence of capacity of temporary facilities on the total costs of blood supply chain. Findings: Changing the capacity of mobile units from 80 to 120 resulted in roughly 10% reduction in the costs, 20% reduction in the optimal number of fixed blood facilities, and 25% reduction in the optimal number of the required mobile blood facilities. Conclusions: While the results of model analysis predict a marginal impact of the capacity of mobile units on the total cost, the capacity of these units is anticipated to considerably influence the optimal number of both permanent and temporary facilities.
- انتشار مقاله: 24-08-1394
- نویسندگان: Abbas Jokar,Seyyed-Mahdi Hosseini-Motlagh
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Hospital Research
- نوع مقاله: Journal Article
- کلمات کلیدی: health system,Social network analysis,Health Services Delivery,Primary Health,Health Services Performance
- چکیده:
- چکیده انگلیسی: Background and Objectives: While social network analysis has left a remarkable practical impact in the healthcare field, the potential implication of this methodology in the primary health domain is poorly researched. Hence, this study aimed to explore the use and usefulness social network analysis in the context of primary health care. Methods: The health volunteers of Imam Ali Health Center in Isfahan city (situated in Central Iran) participated in a plan aimed at helping prevention of depression in 20-45-year-old mothers. Each health volunteer was asked to choose 5 to 20 individuals from the population they covered. Data were collected using a questionnaire in which each health volunteer determined which other volunteers they interacted, and what direction and frequency each interaction represented, during administration of the plan. An interaction was defined as the exchange of information related to the plan between volunteers. A series of network structure variables including degree centrality, betweenness centrality, density degree were calculated. A novel function-oriented network variable, termed activity performance was also introduced and calculated. The activity performance rank of the six lowest-betweenness-centrality-rank individuals were compared with their rank in gatekeeping list for validation of the new networ k variable. Findings: The key members, gatekeepers and week members of the analysed social netwrok were identified. The network was revealed to be relatively homogenous. The average distance between individuals was 2.85 across the whole network and ranged from1.03 to 1.86 within the subnetworks. The individuals’ activity performance ranks were congruent with their betweenness centrality ranks, suggesting the validity of the introduced network variables. Conclusions: Social network analysis can help identify the strength and weaknesses of health-related networks in the primary health context. Elucidation of the network structural characteristics can help improve network interactions, reconciling the network paths, and reinforcing its structure, which in turn can lead to a higher performance of network-based health-related plans. The consistency between activity performance rank and betweenness centrality ranks indicate the validity of the former new variable as a complementary measure be used for a more informative social network analysis.
- انتشار مقاله: 27-01-1392
- نویسندگان: Mohamad-Mohsen Rastegar-Panah,Seyyed-Mahdi Hosseini-Motlagh,Edris Babaei,Fatemeh Noughani
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Hospital Research
- نوع مقاله: Journal Article
- کلمات کلیدی: uncertainty,blood supply chain,Supplementary Blood Center,TOPSIS, Grey Theory
- چکیده:
- چکیده انگلیسی: Background: The efficiency of health system services is a critical measure for societies development. During the last fifty years, the world has witnessed a massive increase in health expenditure, and health-related cost, especially in developing countries, is the main obstacle in the way of advance in health care systems. As a remarkable portion of this cost belongs to blood supply chains, almost any improvement in performance is considered as a critical part of health systems, which contributes to modifying cost-savings and responsiveness policies.
Method: In this paper, a novel multi-criteria decision-making technique is conceptually proposed and presented to location supplementary blood centers so as to prevent disruption to a large extent. In this respect, Grey theory and TOPSIS, a distance-based multiple criteria method, are employed to integrate and evaluate the alternative performance for selecting supplementary blood centers. From a research perspective, TOPSIS method is improved to more effectively tackle grey numbers by presenting a degree of likelihood instead of converting grey numbers into crisp numbers functions, that provides the more flexible ranking procedure.
Results: The real data from Tehran blood transfusion center is applied to validate the method and provide insight into its operational execution, obtained results and validity. Overall, this paper found the proposed hybridized methodology to provide relatively consistent results of top-performing alternatives comparing with the more complicated and less intuitively appealing grey-rough set theory approach.
Conclusion: The proposed hybrid methodology is a useful tool for managers, as well as researchers, who seek to evaluate alternative performance in various studies related to multi-criteria decision making. The technique can also be applied in a regular spreadsheet situation, can take into consideration a variety of metrics, both tangible and intangible, and can be devised with a minimal outside effort from decision-makers and be based completely on archival data if necessary.- انتشار مقاله: 12-11-1397
- نویسندگان: Mohammadreza Ghatreh Samani,Seyyed-Mahdi Hosseini-Motlagh
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Industrial Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Genetic Algorithm,Simulated annealing algorithm,Location-routing problem,Simultaneous pickup and delivery,Two-echelon
- چکیده:
- چکیده انگلیسی: Integrated optimization approach in supply chain has become one of the most important and interesting subjects for researchers in recent years. In this paper, a mathematical model is presented for two-echelon location-routing problem with simultaneous pickup and delivery, so that a layer of facilities with the name of “middle warehouse” are located between main distribution centers and customers. Each customer has demands for commodity reception and delivery simultaneously. In this paper, first a two-echelon integer programming mathematical model, which central/middle storerooms capacities are considered limited, is presented. Then, using genetic and simulated annealing algorithms, a hybrid metaheuristic method is delivered for solving the model. Numerical results of solving sample instances in different sizes confirm the good performance of our approach.
- انتشار مقاله: 03-05-1394
- نویسندگان: MohammadReza Ghatreh Samani,Seyyed-Mahdi Hosseini-Motlagh,Saeed Yaghoubi,Abbas Jokar
- مشاهده