Embodiments are for using sequential set index to determine the root cause location of software issues and problem verification of the software issues. Fail data for a software program is received. The fail data corresponds to a plurality of failed test cases for the software program. It is determined that at least one model in a plurality of models includes at least one case that matches the fail data of the software, each of the plurality of models having one or more cases, the at least one case being in the one or more cases. It is determined that a root cause of the at least one model corresponds to the plurality of failed test cases for the software program.