Fundamentals of the Dempster-Shafer Theory and its Applications to System Safety and Reliability Modelling

The Dempster-Shafter Theory is well-known for its usefulness to express uncertain judgments of experts. This contribution shows how to apply the calculus to safety and reliability modelling, especially to expert judgement; Failure Modes, Effects, and Criticality Analysis; Event Tree Analysis, Fault Tree Analysis, and Reliability Centred Maintenance. Including a tutorial introduction to the Dempster-Shafer Theory, the differences between the Probability and the Dempster-Shafer Theory are discussed widely. U. Rakowsky Fundamentals of the Dempster-Shafer theory and its applications to system safety and reliability modelling RTA # 3-4, 2007, December Special Issue 174 cated outside the system (e.g. observer), exactly one single hypothesis is true; from a subjective point of view of a data source (e.g. expert or operator), it might be uncertain which hypothesis fits best to reality. Therefore, DST makes it possible to model several • single pieces of evidence within single hypothesis relations or • single pieces of evidence within multi hypotheses relations as uncertain assessments of a system in which exactly one hypothesis is objectively true. Both points of view, the objective and the subjective, have to be distinguished clearly. The DST calculus describes the subjective viewpoint as an assessment for an unknown objective fact. By means of a data source, a mapping