Timing-related defects are among the most difficult types of defects to catch while testing software. They are by definition difficult to reproduce and hence they are difficult to debug. Not all components of a software system have timing-related defects. For example, either a parser can analyze an input or it cannot. However, systems that have concurrent threads such as database systems are prone to timingrelated defects. As a result, software developers must tailor testing to exploit vulnerabilities that occur because of threading. This paper presents the Focused Iterative Testing (FIT) approach, which uses a repetitive and iterative approach to find timing-related defects and target product areas with multi