مجله مدیریت تولید و عملیات
سال ششم شماره 1 (پیاپی 10، بهار و تابستان 1394)

The role and importance of supply chain management، has faced with many challenges and problems. Although a comprehensive model of supply chain issues، has not been explained، we have to indicate that issues such as reviewing the theoretical foundations of information systems، marketing، financial management، logistical and organizational relations have been considered by many researchers. The objective of supply chain management is to improve various activities and components to increase overall supply chain system benefits. In order to achieve the overall objectives، many contradictions may occur between the components and different levels of supply chain and the contradictions that these disorders over time، result in decreased strength and competitiveness of the supply chain. Such conflicts، like marketing costs (advertising)، pricing and inventory can occur during the supply chain life cycle. A Game Theory approach with respect to property is the appropriate tool for collaboration in the supply chain. This tool is used for collaborative making in any kind of supply chain such as cooperative supply chain and non-cooperative supply chain. In the present study and assuming a lack of cooperation between different levels of a supply chain، a dynamic game with complete information has been generated. In addition identifying appropriate leaders of various levels of the supply chain is considered. Non-Cooperative dynamic game mode (Stackelberg Game)، for each of the three levels of supply chain including retailers، suppliers and manufacturers are modeled. Depending on the bargaining power and its position in the market، any level of supply chain can make a leader of the following rule. In the present study، the equilibrium model to play Stackelberg game may be led by a leader or leading players and ultimately identifying and modeling the appropriate unlimited three level supply chain are determined.

The tourism industry is becoming one of the world''s largest economical sources، and is expected to become the world''s first industry by 2020. Previous studies have focused on several aspects of this industry including sociology، geography، tourism management and development، but have paid less attention to analytical and quantitative approaches. This study introduces some network analysis techniques and measures aiming at studying the structural characteristics of tourism networks. More specifically، it presents a methodology to analyze tourism destinations network. We apply the methodology to analyze mazandaran’s Tourism destination network، one of the most famous tourism areas of Iran.

In this paper، a supply chain model including production and distribution of perishable crops is introduced. Echelons of the supply chain are farms، fridges and wholesales. Furthermore، the demand can be responded by imports. The planning horizon is finite. Due to the perishable nature of the crops the harvested crops can be held no longer than pre-determined periods. The purpose of this model is to determine optimal planning for production، holding and transportation of each item in each period in order to the total cost is minimized. This model is applied for the case of potato، onion and tomato. The numerical results show that a decrease in total cost and consequently in price of each product can be made via using this model. Saving in water sources is another result of this model. Sensitivity analysis is done to investigate the effects of the key parameters on price and amount of import.

Production planning is one of the most important tasks of production and operations management and decides to determine the optimum amount of production، labor and inventory levels for each period of planning horizon with regard to productive resources and limits. This research presents a multi-product and multi-objective model of production planning with fuzzy parameters and soft constraints regarding the time value of money، inventory level، labor، capacity of machines and warehouse space. The proposed model attempts to maximize profit of the sale and minimize carrying and backordering costs and changes in labor levels. Case study conducted in the aluminum factory، shows the performance of this model comparing the current situation.

According to significance of technology and its role in creating competitive advantage، further attention is required to be paid to technology and its relevant affairs. A basic issue of technology management is the technology acquisition and this research tries to find the most appropriate method of acquiring the technology for frit industry in Yazd province. For this purpose، the literature of this industry has been studied while experts have been interviewed in order to identify factors affecting the acquirement of this technology. Afterward، Fuzzy Delphi technique has been used to modify the identified criteria in order to choose the most important factors. In the next step، Fuzzy DEMATEL technique is used to determine the impact of the criteria and the communications between them. Finally، the fuzzy ANP model has been established to choose the most effective method of acquiring technology out of three general methods of cooperation، production and purchase. The research concludes that “cooperation” is the most preferred method. It should be considered that the participatory methods are selected among technology acquisition multiplicity models in which technical knowledge transfers along with technology transfer. This method can prevent future depending to technology provider. Hence، it is important to pay more attention to this issue because the technical knowledge proficiency has prior condition of the optimal use of technology.

The aim of this paper is to investigate congestion in undesirable outputs. The measurement of congestion is important for performance evaluation. In order to calculate the performance and allocate resources well، it is necessary to measure congestion. Data Envelopment Analysis (DEA) is one of the most appropriate tools for measuring performance. Many researchers have studied this topic by means of DEA. Inefficiency is a necessary condition for the existence of congestion. The managerial issue is defined as “evidence of congestion presents when increase in one input or more can be associated with decrease in one output or more، without worsening any other input or output or proceeding in reverse. However، in the scenario where desirable and undesirable outputs both exist، the definition of congestion is different because the desirable outputs are expected to be more، while the undesirable outputs are expected to be less. Therefore، we cannot apply the current theories and definitions directly for measuring congestion. The previous studies only pay attention to the framework of desirable outputs. In fact، undesirable outputs often accompany desirable outputs in production and services. In this study، a new approach for measuring congestion with undesirable outputs is proposed and applied to analyze congestion of the undesirable outputs and inputs in a department of university. The results indicate that all of inefficient departments that have congestion in undesirable output and also، particular congestion in undesirable outputs has the highest correlation with the efficiency.

A number of methods have been developed to choose the best capital investment projects such as net present value، internal rate of return and etc. Internal rate of return method is probably the most popular method among managers and investors. But despite the popularity there are serious drawbacks and limitations in this method. After decades of efforts made by economists and experts to improve the method and its shortcomings، Magni in 2010 has revealed a new approach that can solves the most of internal rate of return method problems. This paper present a new method which is originated from Magni’s approach but has much more simple calculations and can resolve all the drawbacks of internal rate of return method.

The supply chain network design has attracted the attention of many researchers during recent years. This paper presents a new bi-objective mixed-integer linear programming (MILP) model to integrate procurement، production and distribution planning under uncertainty. This model is set up for the network of a multi-echelon، multi-product، multi-channel، multi-period supply chain with regard to two conflicting objectives، which minimize the costs and minimize the sum of backorders and surpluses of products in all periods using “activity-based costing and the total cost of ownership” and “JIT” concepts، respectively. To solve the presented model، an interactive fuzzy approach is used. The associated results show the amount of purchasing of each supplier، the quantity of producing، the inventory of raw materials and products، backorder or surplus delivery of goods، the mode of transportation، the amount of goods transported between facilities and suppliers used in each period. In addition، a numerical example is presented to demonstrate the applicability of the presented model and exhibit the efficiency of the proposed interactive fuzzy approach. Finally، the results and conclusion are provided.

The design، production and presentation of new products is inevitable for manufacturing companies who wish to linger in the competitive market and continue to grow and develop. On the other hand، New Product Development (NPD) is a complex process and its success depends on many factors. The purpose of this research is to recognize، prioritize and analyze the cause and effect relationship among these factors. In this study، nine factors referred to by many scholars have been analyzed. Twelve academic and industry experts have been surveyed and their opinions have been gathered. In order to prioritize the factors، the Interpretive Structural Modeling (ISM) and to analyze the cause and effect relationship among them، the DEMATEL method has been used. In this study، factors such as «Organizational and Top Management Support»، «Technological Proficiency» and «Rewarding team members» have been recognized as driver factors (causes) and «NPD Strategies»، «Innovation Orientation» and «NPD Process» have been recognized as dependent factors (effects).

Generally supply chain''s investigation has two basic problems. The first problem occurs when the number of suppliers، products and items are very much. Nowadays، due to the complexity of production systems، the suppliers have some limitations. This is the second problem. One of the constraints is that the demands should be completely met by suppliers. In this paper، the mentioned problem is solved by clustering both items and suppliers، and also applying TOPSIS model. The proposed method is performed on a production plant as a case study; also the obtained results are compared with the results of DEA method. The results of both methods are the same.