Possibility theory and fuzzy logic applications to risk assessment problems

摘要

In the process of the risk analysis is common to use the probability to determine the degree of occurrence of an event. In most cases the individuation of main factors of risk in an industrialized area is afflicts by great errors caused by the non complete knowledge either the behavior or the relations among the parameters involved. If the target is to reach a more precise description of phenomenon, we can use fuzzy sets to describe the parameters of the problem and fuzzy measures to growth the knowledge of the problem. The quantities that the Theory of Possibility employs are Necessity, Possibility, Belief and Plausibility; these, when the ignorance associated to a problem is zero, are equal to the classical probability; thus the substance of these quantifiers is to characterize a complex problem decreasing the uncertainty associated. When the uncertainty is zero, the problem isn't uncertain but only imprecise and the probability is enough for a complete description of the phenomenon. The paper will illustrate in which area of the industrial risk assessment, and related case studies the Possibility Theory can be applicate with advantage.