  Combinatorial interaction testing (CIT) is a useful testing technique to
address the interaction of input parameters in software systems. In many
applications, the technique has been used as a systematic sampling technique to
sample the enormous possibilities of test cases. In the last decade, most of
the research activities focused on the generation of CIT test suites as it is a
computationally complex problem. Although promising, less effort has been paid
for the application of CIT. In general, to apply the CIT, practitioners must
identify the input parameters for the Software-under-test (SUT), feed these
parameters to the CIT tool to generate the test suite, and then run those tests
on the application with some pass and fail criteria for verification. Using
this approach, CIT is used as a black-box testing technique without knowing the
effect of the internal code. Although useful, practically, not all the
parameters having the same impact on the SUT. This paper introduces a different
approach to use the CIT as a gray-box testing technique by considering the
internal code structure of the SUT to know the impact of each input parameter
and thus use this impact in the test generation stage. We applied our approach
to five reliable case studies. The results showed that this approach would help
to detect new faults as compared to the equal impact parameter approach.
