ABSTRACT
Fault tree analysis is a widely applied technique that is used in quantitative and qualitative analysis to obtain information about safety of a system. When fault tree events are named, ambiguous nomenclature can create significant impact on the analysis which then yields erroneous results. We emphasize on the usage of correct nomenclature for fault tree events and describe the effects of the failure to do so. Component Fault Tree (CFT) is a type of improvised fault tree used in industries such as the gas turbine and the railway industry. While conducting analysis of CFTs for systems which are part of a product line in an industrial setting, we discovered that, the same basic events had different properties in different products of a product line. This shows that the existing naming convention is not sufficient for unambiguous nomenclature of FT events. Hence, we extend the present naming convention to address such cases. State/Event Fault Trees (SEFTs) are improvised CFTs which enable one to express the state-based failure behavior which was previously not possible by CFTs. We further extend the naming convention for CFTs with an extra field for SEFTs which takes into account the states and events of a component that can be accessed through its outports. Lastly, we illustrate how the naming convention can be applied to a part of SGT 400, a gas turbine developed by Siemens AG, München.
