ANALYSING CONTROL SYSTEMS BY MEANS OF EVENT TREES

Abstract

In the failure analysis of a control system one is nearly always confronted in practice with several different consequences as result of a disturbance in the controlled process and/or a failure in the control system. Often enough one performs such an analysis by means of fault trees. This may lead to incorrect conclusions. In the author's opinion a failure analysis of a control system should start with the construction of event trees. A particular failure mode of the control system can be analysed by means of a fault tree. To illustrate this approach an example is given. A pressure regulating system is analysed by means of event trees.