Method for composing fault tree by digraph

摘要

PURPOSE: A method for automatically synthesizing a fault tree using a digraph is provided to evaluate a risk systematically and scientifically by representing a complex chemical process with the diagraph and automatically writing the fault tree through an automatic diagraph-fault tree transform algorithm. CONSTITUTION: A process flowchart is given(S10). The diagraph is written by including a failure of a node and an apparatus expressing a process variable, and worker's mistake for the given process flowchart(S20). The information for the node and the failure is stored by discriminating the failure data and the node/failure explanation data(S30). A top event defining controllable and uncontrollable change as a numeric value is selected(S40). It is checked/classified that a loop is present on the diagraph and the loop is present in one of the PFFL(Positive Feed Forward Loop), the NFFL(Negative Feed Forward Loop), the PFBL(Positive Feed Backward Loop), and the NFBL(Positive Feed Backward Loop) if the loop is present on the diagraph(S50). The fault tree corresponding to the written diagraph is generated by applying a different fault tree generating rule depending on a situation of the selected top event(S60).