Thomas L. Saaty

He is the inventor, architect, and primary theoretician of the Analytic Hierarchy Process (AHP), a decision-making framework used for large-scale, multiparty, multi-criteria decision analysis, and of the Analytic Network Process (ANP), its generalization to decisions with dependence and feedback. Later on, he generalized the mathematics of the ANP to the Neural Network Process (NNP) with application to neural firing and synthesis but none of them gain such popularity as AHP.