Nimet Yapici Pehlivan

Organizational strategy development in distribution channel management using fuzzy AHP and hierarchical fuzzy TOPSIS

Highlights? The vegetable oil manufacturer company wants to decide the organization strategy to manage the distribution channels. ? We present the methods of FAHP and HFTOPSIS for evaluating and selecting among the five organization strategy models. ? The models include determinants of customer profile, distributor reliability, the position of competitors in market and managerial and financial perspective. ? Hybrid based strategy (KBS) is found as the best choice. Distribution channel management not only consists of choosing distribution channels. In fact, probably the most difficult phase of the distribution management starts after this choice. Determining an appropriate organization strategy for distribution channel management is like a problem of concern to marketing practitioners and academics as well in this phase. In this study, the organization strategy of distribution channel management is developed using fuzzy analytic hierarchy process (FAHP) and hierarchical fuzzy TOPSIS (HFTOPSIS) for an edible-vegetable oils manufacturer firm operating in Turkey. The company distributes its products all over the country. Due to the complex structure of the distribution network, the company wants to decide the organization strategy to manage the distribution channels. In this paper, the methods of FAHP and HFTOPSIS for evaluating and selecting among the five organization strategy models for distribution channel management of vegetable oil manufacturer have been presented. The proposed models include determinants of distribution channel management for edible-vegetable oil industry; (i) customer profile, (ii) distributor reliability, (iii) the position of competitors in market, and (iv) managerial and financial perspective. Using FAHP and HFTOPSIS, hybrid based strategy (KBS), which has the greatest desirability index value after the evaluation among the five alternatives is found as the best choice. Thus, the case of the vegetable oil manufacturer company provides the researchers and practitioners to understand in a better way the importance of developing organization strategy in channel management from a practical point of view.

Fuzzy Multi-Objective Optimization of a Green Supply Chain Network with Risk Management that Includes Environmental Hazards

ABSTRACT Among the leading environmental risks, global climate alteration has become one of the most important controversial issues. Greenhouse gas emissions (CO2, methane, etc.) and air pollution have motivated a need to develop and improve environmental management strategies. As a consequence, environmental sanctions are forcing commercial enterprises to re-consider and re-design supply chain processes in a green way. This article provides a multi-objective model to design a closed-loop supply chain (CLSC) network in a green framework. Our first and second objectives are to minimize all the transportation costs for the supply chains forward and reverse logistics; the third objective is to minimize total CO2 emissions; the fourth objective is to encourage customers to use recyclable materials as an environmental practice. To provide more realistic modeling by treating the uncertainty in decision-makers’ objectives, fuzzy modeling is used in this study. The model is explained and tested via fulfilling a numerical example. In scenario analyses, analytic hierarchy process (AHP), fuzzy AHP (F-AHP), and fuzzy TOPSIS (F-TOPSIS) approaches were applied and compared to evaluate different objectives to guide decision-makers.

A New Tradeoff Model for Fuzzy Supply Chain Network Design and Optimization

ABSTRACT This article proposes a novel mixed integer linear programming model for solving a fuzzy supply chain network (SCN) design problem. This problem includes fuzzy parameters, choosing suppliers according to their quality of raw materials, and the suppliers engagement contracts. There is a tradeoff between raw material quality, and its purchasing and reprocessing costs. If a decision-maker (DM) wishes to work with a supplier that supplies a low-quality raw material, this raw material may be in need of reprocessing. To avoid the reprocessing costs, a supplier that provides a high-quality raw material can be chosen, but in this case the DM faces a high purchasing cost. An integrated fuzzy SCN system that consists of multiple suppliers, manufacturers, distribution centers, and retailers is considered in order to address problems under the aforementioned tradeoffs. Finally, concluding remarks and suggestions for future work are presented.

A Decentralized Model for Allied Closed-Loop Supply Chains: Comparative Analysis of Interactive Fuzzy Programming Approaches

The supply chain network design problem addresses various factors that maximize customers’ demand and minimizes the sum of strategic, tactical, and operational costs. Companies with common activities in their supply chains have started to cooperate with each other to achieve better service levels. Based on this initiative, a multi-level mixed-integer linear programming model is developed that includes two allied supply chains with different decision makers (DM) at two different decision-making levels. The primary aim of this study is to design an allied closed-loop supply chain (CLSC) network that uses some of the same facilities. The secondary aim of this study is to examine this allied CLSC model simultaneously and analyse the impact of the DMs’ objectives based on satisfaction degrees. Various interactive fuzzy programming (IFP) approaches were utilized to examine the presented multi-level CLSC model. A novel IFP approach which is based on the fuzzy analytic hierarchy process (AHP) is proposed. The effectiveness of the proposed IFP approach on the CLSC model is investigated with hypothetical data. The computational results show that the proposed approach obtains higher satisfaction degrees for upper-level DMs than the other approaches.

An integrated fuzzy AHP/DEA approach for performance evaluation of territorial units in Turkey

Due to the differences between regions and sub-regions in the countries, some problems come out especially in economic and social life. The issue of differences of regions has been widely implemented to evaluate the economic performance of Turkey in many disciplines. The objective of this paper is to evaluate the efficiency of 26 sub-regions of NUTS-2 classification using integration Fuzzy Analytic Hierarchy Process (FAHP) with Data Envelopment Analysis (DEA). The integrated FAHP/DEA method comprises two stages. In the first stage, linguistic terms are used to determine the decision makers’ opinion and are converted to quantitative forms by using FAHP methods. Subsequently, in the second stage, DEA method is applied to obtain relative efficiency of sub-regions in Turkey. The integrated FAHP/DEA method is illustrated with a real case study.

Allied Closed-Loop Supply Chain Network Optimization with Interactive Fuzzy Programming Approach

The concept of closed-loop supply chain (CLSC) has started to attract growing attention due to the consumer pressures, environmental awareness, and legislations. Managers in many companies have realized that a well-designed supply chain (SC) can improve the companies’ performance in the market. Thus, a lot of companies start to focus on CLSC issues including remanufacturing, refurbishing, recycling, and disposal of end-of-life products. The body of literature on CLSC management has been overwhelmingly dominated by noncooperative studies. In order to fill up this gap in the literature, we deal with an allied SC network in cooperative environment. With the implementation of allied SCs, companies not only maximize their profit but also minimize their various costs and become more flexible and efficient in the market. Following this motivation, we develop a decentralized multilevel CLSC model for allied SCs. At the first decision level, the plants in allied SCs are considered as the upper-level DMs of the Stackelberg game. At the second level, raw material suppliers, common suppliers, assembly centers, and common collection centers are considered as the lower-level DMs of the Stackelberg game. In order to tackle each decision-maker (DM)’s unique objectives, we propose a new fuzzy analytic hierarchy process (AHP)-based interactive fuzzy programming (IFP) approach. In the IFP approach, upper-level DMs determine the minimum satisfactory level for their own objectives, and by using this value, the lower DMs evaluate their own satisfactory level. A compromise solution can be derived until termination conditions are satisfied. The primary aim of this study is to design a decentralized CLSC network in cooperative environment and to propose a novel IFP approach. Finally, a numerical example is implemented and analyzed in order to demonstrate the efficiency of the proposed approach.

Evaluation of life quality by integrated method of AHP and TOPSIS based on interval type-2 fuzzy sets

In this study, we present an integrated method of Analytical Hierarchy Process based on interval type-2 fuzzy sets (IT2FAHP) and Technique for Order Performance by Similarity to Ideal Solution based on on interval type-2 fuzzy sets (IT2FTOPSIS). The applicability of the proposed integrated method was performed on a case study of evaluation of life quality for 28 European Union Countries and other six countries, Iceland, Macedonia, Montenegro, Serbia, Turkey and Kosovo, in terms of 30 subjective criteria. The weights of the criteria were computed by IT2FAHP and the ranking of life quality for considered countries was constituted by IT2FTOPSIS. Furthermore, the rankings were obtained by using AHP and TOPSIS methods under crisp/ fuzzy environment to show performance of the proposed method.

Efficacy of Frequency Doubling Technology Perimetry in Non-arteritic Anterior Ischaemic Optic Neuropathy with Altitudinal Visual Field Defects

The aim of the study was to evaluate the ability of frequency doubling technology perimetry to detect altitudinal hemifield defects in cases of non-arteritic anterior ischaemic optic neuropathy. Thirty eyes of 24 cases of the disorder with typical altitudinal visual field defects underwent standard automated (Humphrey 24-2) and frequency doubling technology (N-30 threshold) perimetry. For both techniques locations showing a defect of p < 5% were considered abnormal and the mean percentage defect of both the involved and uninvolved hemifields and global visual field parameters were compared. The mean percentage defects for the involved and uninvolved hemifields were comparable (p = 0.1 and p = 0.07, respectively) but there were statistically significant differences in fixation losses and in test duration (p < 0.001 and p < 0.001, respectively) for the two techniques. The authors conclude that frequency doubling technology perimetry is reliable and easily performed in patients with altitudinal visual field defects. The similarity of the extent of visual field defects found using the two techniques suggests that frequency doubling technology perimetry can be used for the rapid detection of altitudinal defects in anterior ischaemic optic neuropathy.