Hybridization of the Ishikawa Method with the PSI Method in an MCDM Environment

The Ishikawa method has been widely used as a qualitative tool for root cause analysis in engineering and quality management; however, its main limitation lies in the difficulty of quantitatively prioritizing the identified causes, which generates uncertainty in decision-making. To overcome this limitation, this study proposes the integration of the Ishikawa method with the Preference Selection Index (PSI) in a multi-criteria decisionmaking (MCDM) environment. This initiative responds to the need for more robust approaches that combine qualitative and quantitative analyses, especially in industrial contexts where complexity and multiplicity of factors affect operational efficiency. The main contribution of this work is to demonstrate, through a case study in a maquiladora, that the combination of Ishikawa and PSI allows for a more precise identification and prioritization of root causes, thus facilitating more effective interventions. The results demonstrate the viability and added value of the hybrid model, in addition to opening up new lines of research aimed at its integration with other MCDM methods and its application in various industrial and service sectors.