This week’s blog post topic covers Pairwise and Combinatorial Testing. I chose this topic because we will soon cover it in class and having some background information prior to any activities involving this method will be useful to relate back to.
Pairwise Testing, also known as All-Pairs Testing, focuses on efficiency by testing every possible pair of input parameters, rather than every single combination. For instance, if you have a form with fields for name, email, and phone number, Pairwise Testing would cover combinations like name and email, name and phone number, and email and phone number. It’s a straightforward way to catch potential bugs without an overwhelming number of test cases. With Combinatorial Testing, it builds on Pairwise Testing by considering combinations of three or more parameters together. Using our form example, Combinatorial Testing would include triples like name, email, and phone number. This comprehensive approach aims to uncover bugs that might only appear with specific combinations of inputs. This testing method aims to optimize efficiency and coverage. Software testing can be time-consuming, especially with numerous parameters and scenarios. Pairwise and Combinatorial Testing streamline the process, allowing you to detect more bugs in less time.
The key benefits to this method is it helps in reducing the number of test cases needed to achieve “good” coverage. Instead of exhaustive testing, you’re strategically covering the most important combinations. Secondly, it helps in identifying interactions between parameters that might lead to unexpected behavior. By testing these combinations, you’re better prepared for real-world usage scenarios.
Of course, there are disadvantages to Pairwise and Combinatorial Testing. One, It can become tedious due to the large number of test cases required to cover all input combinations. Two, It relies on the interaction of pairs of parameters to determine outcomes, but this assumption may not always hold true, potentially missing bugs. And three, additional tests might be necessary to complement pairwise testing, adding extra time and effort to the testing process.
The main challenge when using this method is selecting the correct input parameters. The choice of relevant parameters impacts software behavior. Careful selection ensures thorough test coverage and defect detection. However, accurately determining parameter interactions is equally as difficult, because it could potentially result in the selection of incorrect combinations.
Some of the tools used by teams are PICT, IBM FoCuS, ACTS, Hexawise, Jenny, etc. These tools help automate the test case design process by generating a compact set of parameter value choices as the desired test cases. This is done by applying the all-pairs testing technique, which involves testing all possible combinations of two parameters.
Blog Post: https://testsigma.com/blog/pairwise-testing/
From the blog CS@Worcester – Computer Science Through a Junior by Winston Luu and used with permission of the author. All other rights reserved by the author.