DECISION SUPPORT SYSTEM FOR SERVICE QUALITY ASSESSMENT AT SUSHI XYZ RESTAURANT USING THE FUZZY MAMDANI METHOD

Abstract

Service quality assessment is essential for maintaining the competitiveness of Sushi XYZ restaurant. However, manual evaluations often face challenges such as subjectivity and inconsistency. This study implements the Fuzzy Mamdani method to develop a Decision Support System (DSS) that provides objective and measurable evaluations based on three main criteria: Service Speed, Friendliness, and Cleanliness. The process begins with fuzzification to convert numerical data into fuzzy categories, followed by rule-based inference using IF-THEN logic, and concludes with defuzzification using the centroid method to produce a crisp output value. The results show that Respondents A and E fall into the "Good" category, while Respondent D is classified as "Poor," with recommendations for improvement in Friendliness and Cleanliness. Respondents B and C are in the "Fair" category. This system provides valuable insights for Sushi XYZ management to enhance service quality through time optimization, staff training, and cleanliness maintenance. The Fuzzy Mamdani approach enables systematic, targeted decision-making that supports continuous improvement in service delivery.