Multi-criteria Influence Diagrams – A Tool for the Sequential Group Risk Assessment

Abstract

This chapter describes the use of influence diagrams in the risk assessment and proposes their extension to the group decision making using fuzzy logic, sequential approach and multi-criteria evaluation. Instead of classical Bayesian networks using conditional probability tables that are often difficult or impossible to obtain, a verbal expression of probabilistic uncertainty, represented by fuzzy sets is used in this approach. Influence diagrams are modeling the multistage decision processes and the interrelations among different chance and value nodes as well, enabling the iterative approach to the risk assessment. After the first, independent assessment of the group of experts, this preliminary risk grade is the input in the second step where the adapted risk grade has been adopted based on known evaluations, and interaction among decision makers. The different risk components and decision maker’s attitudes are considered by ordered weighted averages (OWA) operators. This inference engine is illustrated through the assessment of risk caused by improper drug storage in pharmaceutical cold chain by the group of experts in the iterative assessment process.