정보의 부재를 고려하는 다기준 의사결정 모형의 개발과 공급자 선정에의 적용

류시욱 ( Si-wook Ryu ) 대한설비관리학회 2016 대한설비관리학회지 Vol.21 No.4

Supplier selection, which is substantial to make a successful supply chain relationship, is the complex decision making problem with both conflicting multiple criteria and usually several decision makers. This paper extends the existing MCDM (multi-criteria decision making) method to the situation considering lack of information caused by ignorance of knowledge, especially when lack of information happens at all levels including criteria in the hierarchical decision structure. To hurdle the ambiguity and incompleteness of evaluation process, fuzzy linguistic variables are used when the matrices for criteria and alternatives are built. In addition, to deal with lack of information, Demspter-Shafer (DS) evidential theory is applied to the MCDM evaluation scheme. Belief intervals composed of belief function and plausible function are converted to crisp values through the PPT (pignistic probability transformation) method and the quadratic programming with weighted loss objective function. All of the procedures are implemented in detail for a supplier selection example, which shows the newly proposed MCDM evaluation scheme to be applicable and effective.

퍼지 AHP와 퍼지 TOPSIS의 통합과 공급자 선정문제에의 적용

류시욱 ( Si Wook Ryu ) 대한설비관리학회 2012 대한설비관리학회지 Vol.17 No.3

Under many conditions, exact data are inadequate to model real-life situation and fuzzy logic can be incorporated to handle the vagueness of the decision makers. Fuzzy analytic hierarchy process (fuzzy AHP) and fuzzy technique for order performance by similarity to ideal solution (fuzzy TOPSIS) are widely used for tackling multi-criteria decision making (MCDM) problems in real situations for these reasons. Some researches that incorporate the different decision making methods have been introduced in order to compensate the weights among criterion. This paper first presents a hybrid multi-criteria decision making procedure using fuzzy AHP and fuzzy TOPSIS. This proposed procedure is used to solve the supplier selection problem to investigate the applicability of procedure. More specifically, the fuzzy decision matrix is identified by fuzzy TOPSIS and then fuzzy AHP is employed to obtain the crisp values for each alternative to make the final decision. To demonstrate the applicability of the proposed approach, an illustrative example for supplier selection problem is presented and the results are analyzed by comparison of the proposed approach and fuzzy TOPSIS.

퍼지 AHP를 이용한 철도 안전업무 종사자 수행도 평가

류시욱 ( Si Wook Ryu ),이경근 ( Kyung Keun Lee ) 한국경영공학회 2012 한국경영공학회지 Vol.17 No.3

This paper deals with the performance evaluation for railway workers who are in charge of railway safety by using fuzzy AHP (Analytic Hierarchy Process). Zadeh (1965) used to model vagueness and uncertainty in decision making processes arising due to lack of complete information. In this paper, we use the fuzzy set theory when we represent linguistic terms as decision maker preferences. At first, the fuzzy AHP procedure which is basically established by Cheng (1996) is introduced. Cheng (1996) used the Shannon entropy in the process of finding the normalized weights. As well as the Shannon entropy, we present another normalized weighting method that uses summation of each column from the final judgement matrix. For an example, we use the hierarchy model presented by Ryu (2007). We extend his model to the fuzzy environment for the proposed procedures to evaluate the railway workers`` performance. And then for the two normalized weighting methods, we try to explain how the normalized weights can differ according to the fuzzy judgement matrix of the two evaluation criteria and degree of fuzziness (-cut) which is necessary to defuzzify. Lastly, through the numerical result, we emphasize that it is important for a decision maker to choose what values of the fuzzy judgement matrix of the two evaluation criteria and degree of fuzziness.

서로 다른 Fuzzy AHP 방법의 혼합 적용과 FMEA 평가에의 응용

류시욱 ( Si Wook Ryu ) 대한설비관리학회 2013 대한설비관리학회지 Vol.18 No.4

Failure mode and effects analysis (FMEA) provides an effective way for improving product design and process planning by prioritizing potential product and process failures so that preventive measures can be taken in early stages. However, one of the drawbacks of the FMEA is especially the risk priority number (RPN) as determined by multiplying the converted scores of the three predefined factors without considering their relative importance. This paper addresses a compromising measure to mix the existing two fuzzy AHP methods when the three factors with their relative importance should be considered and there are over 10 potential failure odes to be evaluated. A numerical example is shown to explain the procedures and to testify the applicability of the proposal.

TRIZ를 이용한 생산 및 경영 진단 문제해결에서 TOC의 사고프로세스와 AHP의 적용에 관한 연구

류시욱 ( Si Wook Ryu ) 한국경영공학회 2011 한국경영공학회지 Vol.16 No.3

Recently, there are some researches on showing that the TRIZ (Russian abbreviation for Theory of Inventive Problem Solving) can be applied to solve problems in various situations. In addition, the TP (Thinking Process) of the TOC (Theory of Constraints) is useful to find causal problems among several problems which have the cause-and-effect relationships. However, it is important for all companies to decide the priority among problems when multiple causal problems are found. The current reality tree (CRT) in the TP has a similar hierarchy structure as the AHP (Analytic Hierarchy Process). To decide the weights for the priority, the AHP scheme can be adopted. When solutions are found, the TRIZ method is used. For all the procedures, an integrated sequential problem solving flow is developed and at last a real example is introduced to show that the integrated problem solving process can be applied successfully.

철도건설에서 BSC의 KPI도출과 BPM을 위한 프로세스 KPI도출

류시욱(Si-Wook Ryu),안병준(Byung-Jun Ahn),류명욱(Myung-Wook Ryu) 한국철도학회 2006 한국철도학회논문집 Vol.9 No.4

경영 및 생산의 문제진단과 해결방안 도출에 있어 TOC의 TP와 TRIZ의 통합에 관한 연구

류시욱 ( Si Wook Ryu ) 대한설비관리학회 2010 대한설비관리학회지 Vol.15 No.1

To solve complex problems scattered in production and management areas, it is necessary to view relations among the problems in system`s standpoint. Thus, the systematic approach is emphasized in TOC (Theory of Constraints). Thinking process (TP) of TOC is adequate to understand the tangled problems with cause and effect relations. After obtaining undesirable effect (UDE) lists through the interview of top decision maker, current reality tree (CRT) should be drawn to find what effect is a source of the other effects. And then solutions are found using solver`s intuition with the conflict resolution diagram (CRD). This study proposes that an inventive method can be used to find solutions without using intuition. Recently, TRIZ (Russian abbreviation for Theory of Inventive Problem Solving) receives much attention to solve problem inventively and scientifically. In this study, the contradiction matrix and 40 inventive principles are used to overcome the technological contradiction. Lastly, an example for an actual company is also introduced to verify the procedure which comprises TP of TOC and TRIZ steps.

DS/AHP와 GRA의 통합접근법을 이용한 공급자 선정

류시욱 ( Si Wook Ryu ) 대한설비관리학회 2014 대한설비관리학회지 Vol.19 No.4

Supplier selection is one of the most crucial strategic problems to set up a successful supply chain relationship. However, due to rapid changes in the management environment, decision makers often experience lack of information necessary for an exact decision. This paper suggests an integrated MCDM (Multi-Criteria Decision Making) method, using DS/AHP (Dempster-Shafer/Analytic Hierarchy Process) and GRA (Grey Relational Analysis), to deal with lack of information in the supplier selection problem. To obtain the decision matrix, the Dempster-Shafer rule of combination is used with the basic probability assignments (BPA) and the plausibility function. Furthermore, the degree of relations for suppliers are obtained by multiplying grey relational coefficients with inequal weights of criteria. The proposed method is investigated by a numerical example for its applicability and validation.

AHP를 이용한 철도인적오류 특성요인과 배경요인의 평가에 관한 연구

류시욱 ( Si Wook Ryu ) 대한설비관리학회 2007 대한설비관리학회지 Vol.12 No.2

정보 보안 방안 선택을 위한 퍼지 AHP 방법의 비교 검토

이경근 ( Kyung Keun Lee ),류시욱 ( Si Wook Ryu ) 한국정보시스템학회 2010 情報시스템硏究 Vol.19 No.3

Along with advance of information technology, value of information is growing much more than ever. And nearly all organizations pay great attentions to information security to protect their own important informations against every kind of hazardous accidents. Therefore, organizations want to select best information security system among many possible alternatives. For this purpose, several fuzzy AHP decision making approaches can be utilized. In this study, we consider a number of qualitative and quantitative factors to evaluate security systems and then apply three fuzzy AHP approaches for simple case to compare the results from three approaches. We find that final decision depends on both fuzzy AHP methods and degree of fuzziness.