Fault isolator tool for software fault tree analysis

Abstract

Software Fault Tree Analysis (SETA) is a technique used to analyze software for faults that could lead to hazardous conditions in systems which contain software components. A necessary element of a SETA process is the construction of software fault trees based upon the syntactical structure of the software being analyzed. The specific problem addressed by this thesis is how can the process of generating software fault trees based upon the translation of Ada source code files be automated. The approach taken to address this problem was to develop an automated tool that manipulates files created by the Automated Code Translation Tool (ACTT) Ord 93 and Reid 94 developed earlier at the Naval Postgraduate School. The ACTT is an automated tool that translates Ada source code files into statement template tree structures that can be used to construct software fault trees. This thesis presents the Fault Isolator Tool (FIT), an automated process for locating and isolating those parts of a statement template tree structure generated by the ACTI tool that are related to statements in Ada programs that the analyst selects for evaluation. The FIT tool then generates software fault trees in a form compatible with the Fault Tree Editor (FTE), an interactive graphical editor designed by Chuck Lombardo, a computer systems administrator at the Naval Postgraduate School. The FTE was developed for the display, editing, and evaluation of software fault trees.