Interdependence between safety-control policy and multiple-sensor schemes via Dempster-Shafer theory

The Dempster-Shafer (D-S) theory has been gaining popularity in fields where incomplete knowledge is a factor. The author explores the application of the D-S theory in system reliability and safety. Inappropriate application of the D-S theory to safety-control policies can degrade plant safety. This is proven in two phases: (1) a unified combination rule for fusing information on plant states given by independent knowledge sources such as sensors or human operators is developed; and (2) combination rules cannot be chosen in an arbitrary manner, i.e., the best choice of combination rules depends on whether the safety-control policy is fault-warning or safety-preservation.>