فصلنامه مطالعات مدیریت صنعتی
پیاپی 53 (تابستان 1398)

Reducing the cost of wastage and shortage of hospitals' blood products with regard to the compatibility of blood groupsBlood supply chain management is considered one of the main components of the health system of each country. This chain consists of two-component blood collection and supply of products for blood donors has been formed. This article focuses on the issue of the supply of blood products; that tries to provide a mathematical model to reduce waste costs and a shortage of blood products to hospitals. In this model, while meeting the needs of different groups of hospitals, blood in hospitals is minimized inventory costs. A mathematical model in five hospitals affiliated Blood Transfusion Center of East Azerbaijan is implemented. With regard to the compatibility of blood groups and red cell products supply costs and inventory decreased 18% o + blood group also declined to be compatible with other blood types.Keywords: blood supply chain, RBC, compatibility, BTC

The purpose of this study is to consider the importance role of operational and financial variables and also extract these variables in four-echelon supply chain network in a systematic mode. In addition, this study explores the direct and indirect relations of variables, clustering concepts, making co-occurrence networks and calculating micro and macro indices of Scientometrics using co-occurrence analyses. The methodology of the research is content analysis and Scientometrics. Data were collected from four databases (science direct, emerald, wiley, SID) between 2013-2016. Data analyzes were done by Excel, VosViewer and Nodexl. The results of the content analysis extract 106 variables that the most frequent variables were demand, profit and price. In addition, co-occurrence analysis of operational and financial variables shows high Solidarity of the network (more than 80 percent density) that the result confirms the goodness clustering of the variables. Regards to this study, researchers and practitioners can use and employ the results in difference modeling (like: mathematical modeling, structural equation model, …).

Overally location problem could be classified as desirable facility location and undesirable facility location. In the undesirable facility location problem contrary to desirable location, facilities are located far from service receiver facilities as much as possible. The problem of locating such facilities is discussed in this paper. This research is focused on the “not in my backyard” (NIMBY) which refers to the social phenomena in which residents are opposed to locate undesirable facilities around their houses. Examples of such facilities include electric transmission lines and recycling centers. Due to the opposition typically encountered in constructing an undesirable facility, the facility planner should understand the nature of the NIMBY phenomena and consider it as a key factor in the determining facility location. A integer linear model of this problem and a Lagrange relaxation method are proposed in this research. This method relaxes up the hard constraints and adds the constraints to the objective function with a Lagrangian multiplier. To show that the Lagrangian relaxation method is computationally powerful exact solution algorithm and is capable to solve the medium-size problems, the performance of the proposed algorithm is examined by applying it to several test problems.

Land and housing economy have a large proportion of the whole economy and play an important role in the cultural, economic and social community. In all parts of the world, land and houses make a large share of its assets and the proper management of these resources can help country’s economy grow. The housing sector in Iran has faced many problems. Low purchasing power of costumers, price bubble especially in big cities, intense cycles in supply and demand and less on the market for mortgage or rent, more supply than demand and many unfinished projects are examples of problems in the field. In this paper, after explaining the current problems, causal loop diagram and then stock-flow model is presented. After validation of the model, the proposed policies are presented based on model structure and relationships. Presented policies reduce the severity of future cycles and improve equilibrium between supply and demand sectors and help linear and continuous presence of the buyer.

Supplier selection is the process by which firms identify, evaluate, and contract with suppliers. The supplier selection process deploys a tremendous amount of a firm's financial resources. Nowadays, supplying the required resource of organizations has become an important business approach so a competitive advantage may be gained by the selection of the best suppliers to provide products/services more effectively and efficiently. Many models have been developed for solving supplier selection problem. In this paper, in addition to considering the incremental discount strategies, cost of shortages is also considered so far has not been considered. In this model, two objective functions of cost minimization of the buyer, and maximize quality of product is considered. To solve the proposed supplier selection model, an improved harmony search algorithm is used. The results show that the proposed algorithm works properly in the term of both CPU time and the quality of solutions. Finally, some numerical examples for model analyses are presented.

Mobile phone towers strength and coverage after happening natural disaster are one of the most important issues in set covering. Every day advances and developments of mobile phone technology have made the telecommunication industry and transferring equipment more important and subscribers and users of the mobile phones and increasing which requires better planning. So, the subject of coverage ability of the cell phone towers is very important. Natural disasters for example earthquake, flood, storm, landslides and activating volcano affect roads, bridges, communication systems, electrical supplying and availability to facilities. Extensive human casualties and huge economic damages are showing prediction necessity and programming for facing these events preventing crisis occurring This paper develops location and strengthening of cell phone towers to maximize service coverage and minimize the loss of communication if natural disaster happens. In addition, proposed model considers backup and emergency coverage. We present a case study of our approach for disaster planning for disaster scenario in a region of Iran. Numerical experiments demonstrate the significance and applicability of the developed model for actual decision-making problem.

One of the challenges facing the cement industry today, managing the supply chain. Lack of supply chain management, the cement industry has serious problems volatility and the price difference by the manufacturer and the retailer has faced. Usually when a lack of resources and goods in a retail occurs, the customer may go to another retailer. This phenomenon is often called the customer search behavior. This study analyzes a manufacturer and two retailers in a two-echelon supply chain using game theory (Nash equilibrium, balance Stackelberg) with the customer market approach to fars cement industry. The method for the purpose of collecting data item. Enjoying the view of experts, information available on the main site Fars and determine the parameters of the model and software Mathematica functions to solve mathematical equations and plot discussed. The results of this study show that with current conditions and utility functions defined for the issue, to determine wholesale prices for producers in order to maximize profits Is not their own, so the manufacturer must consider market conditions to determine the wholesale price.

Hazardous materials which are materials due to their chemical and physical properties impose significant risk to the safety of people and the environment. It's more complex routing transport of such material than normal materials. The Combination of the two subjects as the problem of locating and routing, it has created unified system to locating- routing problems. These problems determined optimal number and location of facilities at the same time and also set the optimal number of vehicles and their routes. The purpose of this study was design a network for the transportation of hazardous materials and includes supply levels, distribution (hub) and customers. Hence, it presented a mathematical model in order to minimizing costs and risk simultaneously. Hazardous materials sent from supplier to the hubs and deliveries to customers from there via routing by road transportation. It should be mentioned that in proposal model the hubs been locating In order to validate the model, prepared code GAMS In software and for the exact solution, sample problems with various dimensions were produced in the form of smart and random. For this purpose, was written an algorithm design in Matlab software. According to the problem was NP-Hard, presented a hybrid algorithm based on simulated annealing and genetic algorithms to solve large-scale. At the end of research the proposed algorithm were compared with the results of exact solution.

Supply chain is a network consists of several parts and their inter-relationships. To achieve continuous improvement in supply chain, it is necessary to continually evaluate supply chain performance. One of the important points in evaluating the performance, identify weaknesses subunits, considering the relations between the units in system management and balance between the sectors. In this paper, Network Data Envelopment Analysis technique is used for performance evaluation. Identification of inefficient units in the supply chain and improve their performance is of utmost importance. Since the supply chain is made up of different units, improving several unit is impossible. So, setting priorities is necessary to improve the unit. In addition, the selection of Pattern units is important to get an idea on how to improve inefficient units. So, in this work, using Fuzzy Data, a systematic method is defined for benchmarking supply chain, which in addition to evaluating the performance of the entire supply chain and determine efficient and inefficient decision making units, the efficiency of each of the parts of the supply chain is also calculated. This method is used for performance evaluation of the supply chains of Polyethylene pipes and so the communications and the processes of internal wards of their supply chain is reviewed. In the end, using benchmarking technique, improvement priorities are determined for different levels of the supply chain.

Data Envelopment Analysis (DEA) is a powerful analytical technique for measuring the relative efficiency for a set of Decision Making Units (DMUs) based on their inputs and outputs. There are weaknesses in conventional models DEA. Most important of which is the weight shift input and output which makes the efficiency of Decision Making Units with different weights measured. A characteristic of Traditional DEA models is that it allows DMUs to measure their maximum efficiency score with the most favorable weights. As well as the conventional DEA models are not focused network of evaluation units. In this paper we propose to correct the weaknesses the common set of weights (CSW) in network DEA model based on the Goal programming approach. To test the effectiveness of the proposed model and solve real data is used by insurance companies active in Qazvin province. The model presented in this paper units decide on a similar scale with a set of weights for neutral evaluation is common. Proposed approach helps policy makers to better understand the strengths and weaknesses of DMUs and try to promote the strengths and remove weaknesses to improve the efficiency and ranking of given DMUs.