Computerized fault tree construction for improved reliability analysis

Fault Tree Analysis is a well-known method for reliability evaluation of systems. However, manual construction of fault trees is a tedious and time-consuming task. Thus, many researchers tried to get benefit of high speed and accuracy of digital computers to automate this process. Automated construction of fault trees can be very useful in system reliability analysis, especially in design step, where we need to choose the most reliable design out of several design options. In this paper we will present the computer code we have developed for automated fault tree generation. The program is actually the implementation of an approach we have developed for algorithmic construction of fault trees. The main part of this approach is a component-based method for system modeling. In this method, a system is modeled as a set of components connected to each other. Every component is described in a function table. This modeling approach is capable of modeling a wide range of devices and concepts in different types of systems. The model prepared in this part is then used as an input to the “fault tree synthesis algorithm”, and the result is the fault tree for the specified top event. A case study is done for a part of a UAV system. The results generated by the program are compared with the manually constructed fault trees.