DEX Methodology: Thirty three years of qualitative multi-attribute modeling

DEX is a qualitative multi-attribute decision modeling methodology, which is based on an integration of multicriteria decision modeling with rule-based expert systems. The method was conceived 33 years ago. In its lifespan, it has been implemented in a wide range of computer programs that have been used in hundreds of practical applications. In this paper we report on its main methodological concepts, contributions to the theory and practice of decision support, and present a history of its development and evolution.