Endüstri Mühendisliği Bölümü Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12469/48

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Citation - Scopus: 3
Analytic Network Process (anp) for Solar Power Plant Location Problem
(Institute of Industrial Engineers, 2010) Ayağ, Zeki; Samanlıoğlu, Funda
Solar energy is the most readily available source of energy and one of the most important sources of the renewable energy because it is non-polluting and helps in lessening the greenhouse effect. Main problem of establishing a solar power plant is to determine its location. In the presence of many location alternatives and evaluation criteria a multiple-criteria decision making problem arises. In this work the location problem will be solved by using Analytic Network Process (ANP) to figure out the most satisfying alternative. A numerical example is also included to show the proposed methodology in Turkey.
Citation - Scopus: 89
An Analytic Network Process-Based Approach To Concept Evaluation in a New Product Development Environment
(Taylor & Francis, 2007) Ayağ, Zeki; Özdemir, Rifat Gürcan
Selecting the best product concept is one of the most critical tasks in a new product development (NPD) environment. Making decisions at this stage becomes very difficult due to imprecise and uncertain product requirements. So the evaluation process of determining the most satisfying conceptual design has been a very vital issue for companies to survive in fast-growing markets for a long time. Therefore most companies have used various methods to successfully carry out this difficult and time-consuming process. Of these methods an analytic hierarchy process (AHP) has been widely used in multiple-criteria decision-making problems (i.e. concept selection equipment evaluation). In this study however we use an analytic network process (ANP) a more general form of AHP due to the fact that AHP cannot accommodate the variety of interactions dependencies and feedback between higher and lower level elements. Briefly in this paper an ANP-based approach is presented to evaluate a set of conceptual design alternatives in order to reach to the best concept satisfying the needs and expectations of both customers and company. In addition a numerical example is presented to illustrate the proposed approach.
Citation - Scopus: 2
Cad Software Evaluation for Product Design To Exchange Data in a Supply Chain Network
(ExcelingTech Publishers, 2015) Ayağ, Zeki
The sharing information in a supply chain environment especially CAD models and drawings are so important companies. So the selection of the most satisfying computer-aided design (CAD) software which enables to exchange data through supply chain network has been major issues for companies in a supply chain. The selection process of CAD software among the raising number of alternatives in the market has been very vital and critical issue for companies that aim to make their design and engineering related activities automated towards computer integrated manufacturing (CIM) environment. Therefore most companies have used various methods to successfully carry out this difficult and time-consuming process. Of these methods Analytic Hierarchy Process (AHP) has been widely used for Multiple Criteria Decision Making (MCDM) problems in both academic researches and practices. But in some cases due to the vagueness and uncertainty on judgments of the decisionmaker(s) the crisp pair wise comparison in the conventional AHP seems to be insufficient and imprecise to capture the right judgments of decision-maker(s). Therefore a fuzzy logic is introduced in the pair wise comparison of AHP to make up for this deficiency in the conventional AHP called as fuzzy AHP. In this paper a fuzzy AHP-based approach is proposed to evaluate a set of CAD software alternatives in the market to reach the best satisfying one based on the needs of company. © ExcelingTech Pub UK.
Citation - WoS: 12
Citation - Scopus: 18
A Combined Fuzzy Ahp-Goal Programming Approach To Assembly-Line Selection
(IOS Press, 2007) Ayağ, Zeki; Özdemir, Rıfat Gürcan
In mass production assembly-line balancing (ALB) problem has been a critical and repetitive issue for companies for long time. On the other hand equipment selection for stations has also been another important problem at the design stage of an assembly-line system. In this paper both problems are handled simultaneously. Therefore first goal programming (GP) method a well-suited technique is used to develop a preemptive formulation to joint both of the problems when the nature of the problem consists of several conflicting objectives and some mathematical constraints on solutions. Second an AHP method based on fuzzy scales which is incorporated with the GP is also used due to the fact that it takes both qualitative and quantitative judgments of decision-maker(s) into consideration to rank the equipment alternatives for stations by weight. The fuzzy AHP as one of the most commonly used multiple-criteria decision making (MCDM) methods has been effectively used for more than decade in both academic research and practice and takes the vagueness and uncertainty on judgments of decision-maker(s) into consideration due to the fact that the crisp pairwise comparison in the conventional AHP seems to insufficient and imprecise to capture the right judgments of decision-maker(s). In short in this study a combined fuzzy AHP-GP approach is proposed to evaluating assembly-line design alternatives with equipment selection. An integer GP formulation is constructed which also uses the fuzzy AHP scores of equipment alternatives and employs them as one of the goals. Then the mathematical model is solved to find out the ultimate alternative in terms of the minimized equipment cost and the maximized preference measures of decision-maker(s). The proposed approach is also illustrated on a sample case study.
Citation - WoS: 15
Citation - Scopus: 20
A Combined Fuzzy Ahp-Simulation Approach To Cad Software Selection
(Taylor & Francis Ltd, 2010) Ayağ, Zeki
In this paper a combined approach where the fuzzy analytic hierarchy process (AHP) and simulation come together is presented to select the best computer-aided design (CAD) software out of the available options in the market. The fuzzy AHP is used due to the vagueness and uncertainty of the judgements of a decision maker(s) because the crisp pair-wise comparison in the conventional AHP seems to be insufficient and imprecise to capture the right judgements of the decision maker(s). In this study first the fuzzy AHP is used to reduce a possible number of alternatives for the CAD system to an acceptable level for further study simulation analysis. Secondly a simulation generator as an integrated part of the fuzzy AHP is used to try the remaining alternatives on the generated model of a real-life product organisation in which the final alternative will be used. The results of simulation experiments are obtained and then evaluated to reach to the ultimate CAD alternative.
Citation - Scopus: 4
Determining Master Schedule of Surgical Operations by Integer Programming: a Case Study
(Institute of Industrial Engineers, 2010) Samanlıoğlu, Funda; Ayağ, Zeki; Batili, Burcin; Evcimen, Esra; Yılmaz, Gulsah; Atalay, Ozlem
Fixed amounts of available Operating Room (OR) time compatibility of ORs and restrictions related to surgery equipment and surgeon availabilities complicate the process of preparing the master surgical schedule at hospitals. In this research an integer programming model and its application at Etiler World Eye Hospital (in Turkey) are presented in order to create a master surgical schedule that includes the most common surgery types on weekly basis and resolves surgeon equipment and operating room restriction and availability issues. The integer programming model utilizes the available OR time at the hospital by minimizing the total underallocation of OR time with respect to targeted OR time of surgeons taking into consideration surgeon equipment and OR restrictions and availabilities. The mathematical model is then solved using a commercial solver to obtain a weekly master surgical schedule for the hospital.
Citation - WoS: 71
Citation - Scopus: 98
Evaluating Machine Tool Alternatives Through Modified Topsis and Alpha-Cut Based Fuzzy Anp
(Elsevier Science Bv, 2012) Ayağ, Zeki; Özdemir, Rıfat Gürcan
The problem of machine tool selection among available alternatives has been critical issue for most companies in fast-growing markets for a long time. In the presence of many alternatives and selection criteria the problem becomes a multiple-criteria decision making (MCDM) machine tool selection problem. Therefore most companies have utilized various methods to successfully carry out this difficult and time-consuming process. In this work both of the most used MCDM methods the modified TOPSIS and the Analytical Network Process (ANP) are introduced to present a performance analysis on machine tool selection problem. The ANP method is used to determine the relative weights of a set of the evaluation criteria as the modified TOPSIS method is utilized to rank competing machine tool alternatives in terms of their overall performance. Furthermore in this paper we use a fuzzy extension of ANP a more general form of AHP which uses uncertain human preferences as input information in the decision-making process because AHP cannot accommodate the variety of interactions dependencies and feedback between higher and lower level elements. Instead of using the classical eigenvector prioritization method in AHP only employed in the prioritization stage of ANP a fuzzy logic method providing more accuracy on judgments is applied. The resulting fuzzy ANP enhances the potential of the conventional ANP for dealing with imprecise and uncertain human comparison judgments. The proposed approach is also applied for a real-life case in a company. (C) 2012 Elsevier B.V. All rights reserved.
Citation - WoS: 236
Citation - Scopus: 315
A Fuzzy Ahp Approach To Evaluating Machine Tool Alternatives
(Springer, 2006) Ayağ, Zeki; Özdemir, Rifat Gürcan
Selecting process of a machine tool has been very important issue for companies for years because the improper selection of a machine tool might cause of many problems affecting negatively on productivity precision flexibility and company's responsive manufacturing capabilities. On the other hand selecting the best machine tool from its increasing number of existing alternatives in market are multiple-criteria decision making (MCDM) problem in the presence of many quantitative and qualitative attributes. Therefore in this paper an analytic hierarchy process (AHP) is used for machine tool selection problem due to the fact that it has been widely used in evaluating various kinds of MCDM problems in both academic researches and practices. However due to the vagueness and uncertainty on judgments of the decision-maker(s) the crisp pair wise comparison in the conventional AHP seems to insufficient and imprecise to capture the right judgments of decision-maker(s). That is why
Citation - WoS: 56
Citation - Scopus: 67
A Fuzzy Ahp-Promethee Ii Approach for Evaluation of Solar Power Plant Location Alternatives in Turkey
(IOS Press, 2017) Samanlıoğlu, Funda; Ayağ, Zeki
Solar energy produced through a solar power plant is a freely available non-polluting renewable source of energy that reduces the greenhouse effect. Selecting the best location for a solar power plant among several location alternatives is a complicated multiple criteria decision making (MCDM) problem since several potentially conflicting quantitative and qualitative criteria needs to be taken into consideration. In this paper of the most commonly used MCDM methods in literature
Citation - Scopus: 3
A Fuzzy ANP Approach To Evaluate Computer Simulation Packages
(Inderscience Enterprises Ltd., 2016) Ayağ, Zeki
In this study an intelligent approach is presented to help any simulation practitioner to evaluate simulation software alternatives and determine the best satisfying one based on his/her needs. On the other hand this evaluation process is a typical multiple criteria decision making (MCDM) problem in the presence of evaluation criteria and a set of possible alternatives and there are many methods in the literature which have been used to successfully carry out this difficult and time-consuming process. In this paper one of these methods the analytic network process (ANP) method integrated with alpha-cut fuzzy logic is used because it can accommodate the variety of interactions dependencies and feedback between higher and lower level elements rather than analytic hierarchy process (AHP). In addition an alpha-cut fuzzy extension of ANP uses uncertain human preferences as input information in the decision-making process. Instead of using the classical eigenvector prioritisation method in AHP only employed in the prioritisation stage of ANP an alpha-cut fuzzy logic method providing more accuracy on judgements is applied. The resulting alpha-cut fuzzy ANP enhances the potential of the conventional ANP for dealing with imprecise and uncertain human comparison judgements. © Copyright 2016 Inderscience Enterprises Ltd.
Citation - WoS: 11
Citation - Scopus: 17
A Fuzzy Anp-Based Gra Approach To Evaluate Erp Packages
(IGI Global, 2019) Ayağ, Zeki; Yücekaya, Ahmet
One of the major problems that most companies face with during the implementation of an ERP system is to determine the best satisfying ERP software based on their needs and expectations. Because an improperly selected ERP software might lead to time loss and increased costs and in the long run a loss of market share. Therefore the ERP evaluation process for companies becomes to a vital point. On the other hand evaluating ERP software alternatives under a set of criteria leads us to a multiple-criteria decision making (MCDM) problem and needs to use proper MCDM methods. In the current literature a number of the MCDM methods have been proposed to solve these kinds of problems both of which are the analytic network process (ANP) of Saaty and grey relational analysis (GRA) which has been widely used in solving MCDM selection problems in various fields. Moreover in this article the authors used the fuzzy extension of the ANP method to reflect the uncertainty and ambiguity of decision maker(s) into problem in order to reach more reliable solution. As the fuzzy ANP method was used to calculate the priority weights of the evaluation criteria the GRA method with fuzzy interval-values was employed to rank a set of the possible ERP software alternatives. The proposed approach was also validated in a case study to show its applicability to potential readers and practitioners. Copyright © 2019 IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited.
Citation - WoS: 17
Citation - Scopus: 25
Fuzzy Anp-Based Promethee Ii Approach for Evaluation of Machine Tool Alternatives
(IOS Press, 2016) Ayağ, Zeki; Samanlıoğlu, Funda
Machine tool selection process has been a critical issue for companies for years since improper selection of a machine tool might cause many problems affecting negatively the productivity precision flexibility and company's responsive manufacturing capabilities. On the other hand selecting the best machine tool from its increasing number of existing alternatives in the market is a multiple-criteria decision making (MCDM) problem in the presence of many quantitative and qualitative attributes. Therefore most companies have utilized various methods to successfully carry out this difficult and time-consuming process. In this paper both of the most used MCDM methods
Citation - WoS: 43
Citation - Scopus: 51
A Fuzzy Qfd Approach To Determine Supply Chain Management Strategies in the Dairy Industry
(Springer, 2013) Ayağ, Zeki; Samanlıoğlu, Funda; Büyükozkan, Gülçin
The aim of this study is to identify the crucial logistics requirements and supply chain management (SCM) strategies for the dairy industry. For product or service development quality function deployment (QFD) is a useful approach to maximize customer satisfaction. The determination of design requirements and supply chain management strategies are important issues during QFD processes for product or service design. For this reason a fuzzy QFD methodology is proposed in this study to determine these aspects and to improve customer satisfaction. Qualitative information is converted firstly into quantitative parameters and then this data is combined with other quantitative data to parameterize two multi-objective mathematical programming models. In the first model the most important logistic requirements for the company are determined based on total technical importance total cost total feasibility and total value increment objectives and in the second model based on these objectives appropriate supply chain management strategies are determined. Finally a case study from the Turkish dairy industry is given to illustrate the proposed approach.
Citation - WoS: 140
Citation - Scopus: 178
A Hybrid Approach To Concept Selection Through Fuzzy Analytic Network Process
(Pergamon-Elsevier Science Ltd, 2009) Ayağ, Zeki; Özdemir, Rıfat Gürcan
Evaluating conceptual design alternatives in a new product development (NPD) environment has been one of the most critical issues for many companies which try to survive in the fast-growing world markets. Therefore most companies have used various methods to successfully carry out this difficult and time-consuming evaluation process. Of these methods analytic hierarchy process (AHP) has been widely used in multiple-criteria decision-making (MCDM) problems. But in this study we used analytical network process (ANP) a more general form of AHP instead of AHP due to the fact that AHP cannot accommodate the variety of interactions dependencies and feedback between higher and lower level elements. Furthermore in some cases due to the vagueness and uncertainty on the judgments of a decision-maker the crisp pairwise comparison in the conventional ANP is insufficient and imprecise to capture the right judgments of the decision-maker. Therefore a fuzzy logic is introduced in the pairwise comparison of ANP to make up for this deficiency in the conventional ANP and is called as fuzzy ANP. In short in this paper a fuzzy ANP-based approach is proposed to evaluate a set of conceptual design alternatives developed in a NPD environment in order to reach to the best one satisfying both the needs and expectations of customers and the engineering specifications of company. In addition a numerical example is presented to illustrate the proposed approach. (C) 2008 Elsevier Ltd. All rights reserved.
Citation - WoS: 45
Citation - Scopus: 59
A Hybrid Approach To Machine-Tool Selection Through Ahp and Simulation
(Taylor & Francis, 2007) Ayağ, Zeki
The selection process of a machine tool has been a critical issue for companies for years because the improper selection of a machine tool might cause many problems having a negative effect on productivity precision flexibility and a company's responsive manufacturing capabilities. Therefore in this paper to determine the best machine tool satisfying the needs and expectations of a manufacturing organization among a set of possible alternatives in the market a hybrid approach is proposed which integrates an analytic hierarchy process (AHP) with simulation techniques. The AHP as one of the most commonly used multiple criteria decision-making methods is used to narrow down all possible machine tool alternatives in the market by eliminating those whose scores (or weights) are smaller than a determined value obtained under certain circumstances. Then a simulation generator is used first to automatically model a manufacturing organization where the ultimate machine tool will be used and second to try each alternative remaining from the AHP as a scenario on the generated model. Finally the final alternative is selected by using the unit investment cost ratio which is calculated by dividing the investment cost per year of each alternative by the additional number of produced units obtained from the simulation experiment of the relevant alternative.
Citation - WoS: 44
Citation - Scopus: 54
An Integrated Approach To Concept Evaluation in a New Product Development
(Springer, 2016) Ayağ, Zeki
A new product development (NPD) process can be thought as a comprehensive process in which the design is progressively detailed through a series of phases. At the end of each phase a design review is held to approve the design and release or not it to the next level. As one of these phases concept selection aiming to select the most appropriate concept for further development is conducted earlier in the process. As the further development progresses on a selected concept it becomes more difficult to make design changes in terms of cost and schedule dimensions and therefore selecting the best concept among a set of available alternatives has been an important issue for companies. On the other hand in the presence of many alternatives and selection criteria the selection problem becomes a multiple-criteria decision making concept selection problem. To solve this problem in this work an integrated approach bringing two popular methods together: the modified technique for order preference by similarity to ideal solution (TOPSIS) and the analytical network process (ANP). The ANP method is used to determine the relative weights of a set of quantitative and qualitative evaluation criteria as the modified TOPSIS method utilized to rank competing concept alternatives. In addition a real example is presented to demonstrate the effectiveness and applicability of the proposed approach for potential practitioners and readers.
Citation - WoS: 16
Citation - Scopus: 23
An Integrated Approach To Evaluating Assembly-Line Design Alternatives With Equipment Selection
(Taylor & Francis Ltd, 2011) Özdemir, Rıfat Gürcan; Ayağ, Zeki
The design and implementation of assembly-line systems have been critical issues for companies since the first assembly-line was started at the Ford Highland Plant in 1913. From that time onwards most companies have met with various problems at the design and implementation stages of assembly-line systems two of which are the allocation of different work elements to various workstations and the proper equipment selection for workstations. Therefore in this article to overcome both the above-mentioned problems we propose an integrated approach in which a branch and bound algorithm and the analytic hierarchy process (AHP) method are used together. First the branch and bound algorithm is used to generate a list of assembly-line design alternatives. Then the generated alternatives are evaluated using the AHP method to determine an optimum solution (the best alternative) at minimum equipment cost. The AHP method is one of the most commonly used multiple-criteria decision-making methods in the literature and evaluates both qualitative and quantitative evaluation criteria represented in a hierarchical form. The proposed approach is also illustrated on a sample case study.
Citation - Scopus: 1
An Intelligent Approach To Cam Software Selection
(IEEE, 2012) Ayağ, Zeki
In this paper an intelligent approach is presented to help the companies select most suitable CAM software for their current and future needs. For this purpose fuzzy AHP method is used to carry out CAM selection process more effectively easily and applicable for a company. Shortly the objectives of the research are
Citation - WoS: 116
Citation - Scopus: 154
An Intelligent Approach To Erp Software Selection Through Fuzzy Anp
(Taylor & Francis, 2007) Ayağ, Zeki; Özdemir, Rıfat Gürcan
During the implementations of enterprise resource planning (ERP) systems most companies have experienced some problems one of which is how to determine the best ERP software satisfying their needs and expectations. Because improperly selected ERP software may have an impact on the time required and the costs and market share of a company selecting the best desirable ERP software has been the most critical problem for a long time. On the other hand selecting ERP software is a multiple-criteria decision-making (MCDM) problem and in the literature many methods have been introduced to evaluate this kind of problem one of which is the analytic hierarchy process (AHP) which has been widely used in MCDM selection problems. However in this paper we use a fuzzy extension of an analytic network process (ANP) a more general form of AHP which uses uncertain human preferences as input information in the decision-making process because the AHP cannot accommodate the variety of interactions dependencies and feedback between higher- and lower-level elements. Instead of using the classical eigenvector prioritization method in the AHP only employed in the prioritization stage of ANP a fuzzy-logic method providing more accuracy on judgements is applied. The resulting fuzzy ANP enhances the potential of the conventional ANP for dealing with imprecise and uncertain human comparison judgements. In short in this paper an intelligent approach to ERP software selection through a fuzzy ANP is proposed by taking into consideration quantitative and qualitative elements to evaluate ERP software alternatives.
Citation - WoS: 49
Citation - Scopus: 64
An Intelligent Approach To Machine Tool Selection Through Fuzzy Analytic Network Process
(Springer, 2011) Ayağ, Zeki; Özdemir, Rıfat Gürcan
In this study we utilize analytic network process (ANP) a more general form of AHP for justifying stand-alone machine tools out of available alternatives in market due to the fact that AHP cannot accommodate the variety of interactions dependencies and feedback between higher and lower level elements. However due to the vagueness and uncertainty on judgments of a decision-maker the crisp pair wise comparison in the conventional ANP seems to be insufficient and imprecise to capture the right judgments of the decision-maker. That is why also in this paper fuzzy number logic is introduced in the pair wise comparison of ANP to make up for this deficiency in the ANP. In short here an intelligent approach to machine tool selection (MTS) problem through fuzzy ANP is proposed to improve the imprecise ranking of company's requirements which is based on the conventional ANP. In order to reach to final solution a preference ratio (PR) analysis is done by using the results of the fuzzy ANP and investment costs of alternatives. In addition a numerical example is presented to illustrate the proposed approach.

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