Ayberk Soyer

Risk prioritization in Failure Mode and Effects Analysis using interval type-2 fuzzy sets

A new fuzzy FMEA approach based on IT2 fuzzy sets is proposed.The approach introduces a new aggregation method.The approach utilizes an α-cut based aggregation operator for the first time.The approach introduces a practical method for ranking overall priority values.Comparisons show that the approach provides a satisfactory modeling of uncertainty. The analysis of failure modes and their effects generally requires dealing with uncertainty and subjectivity inherent in the risk assessment process. A review of the literature reveals that although a number of studies have examined these issues, none of them have explicitly studied the variation in one experts understanding (intra-personal uncertainty) and the variations in the understanding among experts (inter-personal uncertainty) together. To address this problem, this paper proposes a new fuzzy FMEA approach based on IT2 fuzzy sets, which has the ability to capture both intra-personal and inter-personal uncertainty. The approach introduces three methods that are new for the analysis of failure modes. First, to provide a more accurate representation of the aggregated data by preserving the variations among the individual judgments a new aggregation method is suggested. It transforms individual judgments in form of intervals into a group judgment in form of an IT2 FN. Second, to allow considering optimal weights for the risk factors and thereby developing more flexible structures for their synthesis, an α-cut based ordered weighted averaging operator is adapted. Finally, to rank failure modes on a continuous scale and reflect subtle differences in the assessments properly, a ranking method for IT2 FNs based on α-cuts is adopted. The applicability and effectiveness of the proposed approach is demonstrated by an illustrative example. Comparisons with the results of crisp- and fuzzy-based methods demonstrate that the proposed approach offers additional flexibility to the experts in making judgments and provides a better modeling of uncertainty.

Identifying strategic management concepts: An analytic network process approach

This paper presents an approach to the identification of an organizations strategic management concepts (SMCs) - mission, vision, values and competences. The highly qualitative relationships among these concepts are operationalized using the Analytic Network Process (ANP). As ANP captures the outcome of dependence and feedback between components of elements, the proposed approach enables us to handle indirect relationships and complex interactions existing among the SMCs. The alternatives with the highest overall priorities, resulting from the ANP, are selected as the organizations most dominant SMC set. To improve the quality of the decision further analysis of the ANP results is suggested. Accordingly, alternative concept sets are derived by applying two approaches - bottom-up and top-down. The bottom-up approach indicates an explorative perspective where only common values and core competences held by the organization are used to identify the corresponding mission and vision statements. On the other hand, the top-down approach indicates a normative perspective where the necessary values and competences are determined according to a given desired vision statement. The proposed ANP approach has been applied to the Industrial Engineering Department (IED) of Istanbul Technical University. In light of the dominant, bottom-up and top-down sets, a final set of SMCs has been suggested for the IED.

A fuzzy approach to value and culture assessment and an application

This paper presents a fuzzy approach to the identification of organizational values and culture. The proposed approach has been developed from crisp assessment methods in the literature and has been applied to the Industrial Engineering Department (IED) at a state university in Turkey. Highly subjective judgments and ambiguity regarding the presence of values and the culture type of the organization resulting from these values suggest the necessity of using a fuzzy approach. Where the uncertainty arises from the inability to perform adequate measurements, fuzzy sets provide a mathematical method of representing such uncertainties. Applying the fuzzy approach, organizational values which are common, and should be common in the IED, are identified and these values are organized into four generic culture types - adhocracy culture, market culture, clan culture and hierarchy culture - stating in which culture type the IED belongs. Finally the uncertainties of the culture sets are quantified by the measure of fuzzy entropy.

A Fuzzy Analytic Network Process Approach

This chapter describes the Analytical Network Process (ANP), a multi-criteria prioritization method to support decision making in complex and uncertain environments and suggests a fuzzy analytic network process (FANP) approach for prioritizing decision elements. The proposed fuzzy set theoretic method accommodates fuzziness in the supermatrix computations and thereby provides the opportunity to capture the uncertainty associated with the cumulative influence of each factor on every other factor with which it interacts. As its comparison to current methods demonstrates, the method successfully derives meaningful priorities from complex and uncertain decision structures.

Failure Mode and Effects Analysis Under Uncertainty: A Literature Review and Tutorial

The multidimensional nature of risks as well as substantial uncertainties and subjectivities inherent in the risk assessment process led a growing number of researchers to develop alternative approaches for failure mode and effects analysis. The purpose of this chapter is to provide a comprehensive review of the multi-criteria approaches proposed for failure mode and effects analysis under uncertainty and offer a brief tutorial for those who are interested in these approaches.

A new approach to DEMATEL based on interval-valued hesitant fuzzy sets

Abstract Decision-Making Trial and Evaluation Laboratory is a widely used method to analyze and visualize the structure of complex systems through matrices and digraphs. The method typically requires dealing with substantial uncertainties and subjectivities inherent in the judgment process. A review of the literature shows that several extensions of DEMATEL have been suggested so far dealing with a variety of sources of uncertainty. However, the uncertainty originating from the human doubt that might arise in the assignment of membership degrees during the assessments is partly or entirely ignored in these studies. To address this problem, this study proposes a new interval-valued hesitant fuzzy approach to DEMATEL, which has the ability to explicitly deal with hesitancy in expert assessments and offer a better representation of uncertainty. To justify the effectiveness and usefulness of the proposed approach, an illustrative example is provided where the proposed approach is compared to the classical crisp and fuzzy DEMATEL approaches.

Analyzing Dynamic Capabilities via Fuzzy Cognitive Maps

Today, free trade, internet, and mobile technologies have given rise to global markets with high levels of change. In order to survive in such fluid environments, firms need to be able to quickly adapt themselves to rapid changes. The concept of “dynamic capabilities ” deals with the organizational capacity to understand the need for change, plan response to change, and finally, implement these plans. Although dynamic capabilities are crucial for the survival of an organization, there is no comprehensive study of the factors related to dynamic capabilities and their effect on a firm’s success. Complexity and vagueness of these concepts precludes developing a comprehensive model. The computational intelligence techniques such as fuzzy models, artificial neural networks, and genetic algorithms can be utilized to handle this complexity and vagueness. Therefore, a Fuzzy Cognitive Map based (FCM-based) model is proposed in this chapter to overcome the modeling difficulty. The factors related to dynamic capabilities, which are collected from an extensive literature review, are defined as concepts and their fuzzy relations are represented as causal links in a graph structure.

Overcoming Path Dependency and “Lock-In”: In Competence Building and Competence Leveraging Processes

Abstract Competence-Based Management (CBM) theory and research suggest that a firm’s competence building and leveraging processes are key factors influencing its competitive success. To achieve sustained competitive success, a firm’s competence building processes must continuously renew and extend the competences a firm has and can leverage. However, the ability of a firm to sustain strategically adequate levels of competence building – while also maintaining strategically successful competence leveraging – may be limited by various self-reinforcing managerial and organizational mechanisms that can arise from competence leveraging processes. In this paper we focus on certain managerial behaviors that may create path dependencies that lead an organization to become “locked-in” to its current competence leveraging processes and to neglect essential competence building, resulting in an inability to renew competences at a strategically adequate level and eventually in competitive failure. In order to avoid such consequences, the management literature suggests that organizations must cultivate dynamic capabilities to overcome tendencies toward lock-in and to sustain ongoing competence building. This study investigates ways in which firms can maintain healthy competence building processes by avoiding lock-ins, especially those resulting from self-reinforcing managerial behaviors. A case study of successful competence-renewing processes in a home improvement retailing company helps to amplify the components of dynamic capabilities and to illustrate the insights that emerge from our study.