A. Yesim Yayla

Use of ANP weighted crisp and fuzzy QFD for product development

Quality Function Deployment (QFD) is a popular planning method often used to transform customer demands/requirements into the technical characteristics of a new or improved product or service. In order to better capture (and represent) the multifarious relationships between customer requirements and technical characteristics, and the relative weights among customer requirements, in this study a hybrid analytic network process (ANP)-weighted fuzzy methodology is proposed. The goal is to synthesize renowned capabilities of ANP and fuzzy logic to better rank technical characteristics of a product (or a service) while implementing QFD. To demonstrate the viability of the proposed methodology a real-world scenario, where a new equipment to squeeze the polyethylene pipes to stop the gas flow without damaging the pipes, is developed. The ranking of technical characteristics of the product is calculated using both crisp and fuzzy weights for illustration and comparison purposes.

MULTI-CRITERIA DECISION-MAKING METHODS FOR SUPPLIER SELECTION: A LITERATURE REVIEW

A firm’s multi-criteria decision-making (MCDM) process is important because of its need to select and work with various suppliers. The process identifies the problems associated with selecting the supplier, , determining convenient criteria, expressing interactions clearly, and usage. These are all suitable methods for finding a solution to these MCDM problems. Considering more than one criterion (and even the sub-criteria of these criteria) during supplier selection makes the selection uncertain. Conventional methods cannot generate a realistic solution to the problem. Using MCDM methods considerably simplifies solving the problem, and enables decision-makers to make better decisions. In this study, a literature review was performed on MCDM methods used between 2001 and 2014 for the supplier selection problem. MCDM methods used in supplier selection are categorised into three main methods, and a summary table of the reviewed studies is presented.

A Choquet integral-based model for sustainable performance of suppliers

The supplier selection process of a company depends on numerous criteria which can have differing importance factors. Solving this kind of multiple criteria decision making (MCDM) problem is essential for the long-term strategy of a company. While this problem is examined numerous times throughout the years, the consideration of involving economic, social and environmental factors, i.e. sustainability is becoming a growing necessity for this effort, especially in the recent years. We propose a Choquet integral based fuzzy model to use the data we obtain by converting the linguistic terms of perceived subcontractor performance values to trapezoidal fuzzy numbers. After the performance criteria values are normalized by the fuzzy integral, they are defuzzified into single data points which helps an evaluator to compare. A case study involving a curtain wall company in Turkey (and its 4 subcontractors) is used to demonstrate the effectiveness of the method. The defuzzified results showed which subcontractor is the optimal choice among 4 subcontractors and 17 criteria.

White goods brand selection by using Generalized Choquet Integral

White goods brand selection decision have become a multi-criteria decision making problem depending on the variety of customer demands and developments at the white goods technology recently. In this study, the selection of the best among the alternative white goods brand is handled as a Multi Criteria Decision Making (MCDM) problem. Within the scope of this study, alternative three white goods brands (A, B, C) are evaluated. Firstly in the scope of the evaluation, a decision team is created as formed by two persons from three families who confronted with such kind of a choice problem. Common view of the decision team is taken for generating hierarchical decision model to be used in evaluation of alternative white goods brands. The Generalized Choquet Integral (GCI) method, being one of the MCDM methods, is used at solution of the problem. At the end of the study, obtained results and evaluations are included.

FUZZY ANALITIC NETWORK PROCESS BASED MULTI CRITERIA DECISION MAKING METHODOLOGY FOR A FAMILY AUTOMOBILE PURCHASING DECISION

Nowadays, in parallel with the advancing technology, automobiles that have substantially advanced technological properties are being manufactured. Intended uses of the automobiles have been changing in our days in contrast to 1960s when automobiles were only used for transportation. Consumers, in our day and age, expect profoundly different properties from an automobile. In this context, more than one criterion become effective on making decision on purchasing an automobile that has the required properties. In such a kind of decision problem, making use of Multi Criteria Decision Making (MCDM) methods will ease the solution of the problem and will enable the decision makers to make right decisions. In this study, fuzzy Analytic Network Process (ANP) method, one of the MCDM methods, is used in automobile purchasing decision making. After determining decision criteria and alternatives, network structure of the automobile selection decision problem is formed, and by using fuzzy ANP method, the best one is selected among three alternative automobiles that are in the same segment and are very approximate to each other in terms of their properties and prices. OPSOMMING Motorvoertuie word in die huidige tydsgewrig deur vervaardigers met gevorderde tegnologiese eienskappe toegerus. Gevolglik word meer as ʼn enkele kriterium deur voertuiggebruikers aangewend om ʼn moderne model te evalueer. Sodanige evaluering word in hierdie navorsing gebaseer op ʼn wasige analitiese netwerk metode. Nadat alle besluitvormingskriteria en alternatiewe vasgele is, word die wasige model gebruik by die seleksie van ʼn bepaalde voertuig uit ʼn monster van drie soortgelyke voertuie. a a a a a a a a a a A A A A A

Performance evaluation of ERP implementation by using fuzzy MCDM

In this study, an ERP implementation project risks analysis problem in a Turkish automotive supplier firm is handled. To determine the risk criteria we benefited from the literature, experts and ERP software users. The handled problem is solved by using fuzzy-AHP methodology. Then a sensitivity analysis is performed to evaluate our risk analysis methodology and to validate the results specifically for our case firm.