A new look at uncertainty analysis

The authors look at uncertainty from a system point of view. They characterize a system by its description and its behavior. The description is composed of structural and functional properties. These properties reveal the hierarchic characters of the system. Behavior is characterized by observing the pattern of change of the description. In practice, structure and function are represented by parameters, and behavior is represented by models. Uncertainties arise from the inability to provide a complete and precise structural and functional hierarchy and the inability to construct a model for predicting its behavior. This lack of precise and complete knowledge is the source of uncertainties, which are translated to uncertainties about parameters and models. Qualitative and quantitative representation of uncertainty have been considered. In the paper probabilistic and nonprobabilistic measures of uncertainty have been reviewed