Application of Hazard and Operability Studies (HAZOP) to Failure Analysis

摘要

A failure analysis always has physical aspects, such as evidence examination and laboratory testing. The process of determining the cause of a failure will benefit from conducting these tasks within a structure or framework such as a fault tree. In a fault tree the failure is at the top of the tree and the branches lead to possible causes. The fault tree must be exhaustive so that the branch associated with the most probable cause exists. A method for identifying potential process problems before they happen, called HAZOP, can be adapted to fault trees. The HAZOP method involves identifying a process or sequence of events, then for each part of the process or each event, considering what happens if that process or event is perturbed. In this study, it is shown how the HAZOP method can be used to develop an exhaustive fault tree. Once the fault tree is developed, the most probable cause of the failure is determined by appropriately analyzing each branch of the fault tree. The method is illustrated using a case study of a water escape at a separated joint in a PVC water main.