A HYBRID NEURO-FUZZY MODEL FOR ASSESSING BANK BORROWER CREDITWORTHINESS

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Viktor Denysenko
Alina Zaitseva
Karina Brovchenko

Abstract

Introduction. In the context of growing macroeconomic instability, digital transformation, and increasing uncertainty in financial markets, the problem of ensuring the reliability of lending decisions and minimizing credit risk has become particularly relevant. Traditional approaches to assessing borrower creditworthiness are largely based on statistical and scoring methods that require significant volumes of historical data and often fail to account for the uncertainty, nonlinearity, and qualitative characteristics inherent in borrowers’ behavior. Under such conditions, the application of intelligent decision-support methods based on fuzzy logic and artificial intelligence technologies becomes increasingly important.


Purpose. The purpose of this study is to analyze the peculiarities of applying fuzzy approaches to borrower creditworthiness assessment and to develop a hybrid neuro-fuzzy model based on the Mamdani algorithm and the Adaptive Neuro-Fuzzy Inference System (ANFIS). The proposed model is aimed at improving the accuracy and interpretability of credit risk assessment by integrating quantitative and qualitative borrower characteristics into a unified decision-support framework.


Results. The study proposes a two-level hybrid neuro-fuzzy model for assessing bank borrower creditworthiness. At the first level, individual indicators characterizing the borrower's social status, financial condition, debt servicing quality, and lending conditions are aggregated into corresponding sub-indices using the Mamdani fuzzy inference algorithm. At the second level, the obtained sub-indices are integrated into a single creditworthiness indicator using ANFIS, which enables the automatic adjustment of membership functions and identification of nonlinear dependencies between factors.


The proposed model is characterized by a hierarchical structure and a high degree of adaptability, allowing the composition of input variables to be modified depending on the type of loan product, including mortgage, consumer, and automobile lending. The architecture of the model was tested using synthetically generated datasets comprising 500 conditional borrowers. The results demonstrated that the implementation of ANFIS at the aggregation stage reduced the root mean square error by 42.6% and decreased the mean absolute percentage error from 11.4% to 6.2% compared with the classical expert-based Mamdani system.


The developed approach allows simultaneous consideration of quantitative and qualitative borrower characteristics, eliminates rigid threshold limitations of traditional scoring methods, and provides a transparent interpretation of the obtained results. In addition, the model is capable of identifying compensation effects among individual factors and adapting to changes in the external economic environment.


Conclusions. The findings confirm the effectiveness of applying hybrid neuro-fuzzy approaches to borrower creditworthiness assessment under conditions of uncertainty and incomplete information. The proposed model combines the interpretability of expert fuzzy systems with the predictive capabilities of adaptive neuro-fuzzy technologies, thereby improving the quality of credit decision-making and enhancing the efficiency of bank credit risk management systems. The practical implementation of the developed model can contribute to reducing the share of non-performing loans and increasing the resilience of banking institutions to macroeconomic shocks. Future research should focus on validating the model using real banking data and comparing its performance with modern machine learning methods, including XGBoost, Random Forest, and deep neural networks.

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References

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