Abstract: Software reliability is directly relevant to the count of faults in software. Fault localization is the key to detect and eliminate the faults. Execution traccbased fault localization is of great significance because it can be integrated well with automatic software testing. Proposed the framework of execution traccbased fault localization FLOC, which can be divided into four components; organization of execution trace, selection of execution trace, computation of suspiciousness, and evaluation of the output. The typical current execution trace-based approaches were described and compared in FL0C. Finally some improvements were proposed according to FLOC. The purpose of this paper is to compare the advantages and disadvantages of those localization approaches in a unified framework,and provide some improvements on those approaches.

Key words: Software debugging, Fault localization, Execution trace, Similarity degree, Suspiciousness ratio