Failure Modes and Effects Analysis (to be referred to as FMEA, from this point) is the technique of analyzing any product or its stages of development in an anticipating manner, so as to increase the overall end user satisfaction along with the productivity of the producing unit. Software FMEA uses the same concept of analysis, over the various development cycle processes that go into producing a robust, compatible and reliable software system for a given set of requirements and specifications. 
The tool in question, does nothing but evaluates the possible errors and anomalies that might crop up while the software development is still under process. At the end, it gives a qualitative measure of the risks involved. This measure, in the form of the Risk Priority Number(RPN) can be used to prioritize the failure cases, and can be made use of later to take necessary measure to ensure maximum functionality and productivity.