Pairwise test case generator- choosing what and how to test judiciously

This is one of most commonly sought after question (be it in testing projects or even when an interviewer wants to test the tester!) is “How do you choose what to test and how do you ensure test coverage when time and other resources are limited and you need to get the best out of pressing schedules?”

Well, one obvious answer is to base on experience based test selection.

But from the Test Coverage perspective, a powerful mechanism exists to judiciously and intelligently reduce the mind blowing number of possible test cases to a few. Pairwise Testing- some of us know it, and wikipedia always says more for the rest of us.

There may be other strategies and techniques but my favorite is the pairwise testing technique. At TestersDesk, the pairwise test case generator is designed for such occasions and you can reduce the total number of test combinations to an intelligent few.Take a case where a particular feature (let us say 'printing') has to be tested and you want to determine how printing your web-page works with different operating systems, browsers, paper sizes etc.

Let us say following are the test parameters and their values:

OS:Win XP,Redhat Linux,Macintosh
Browser:IE 6,IE 7,Firefox,Opera
Orientation:Portrait,Landscape
Size:A3,A4,A5
Color:Mono,Multicolor

The total combinations that need to be tested are 3 operating systems X 4 browsers X 2 types of Orientation X 3 sizes X 2 types of Color, that is, 144.

Pairwise Testing is a significant advancement in the evolution of Test Case Design techniques, especially those that deal with reduction of test combinations when the total number of combinations becomes too large to test.

Research has proven that most of the software defects occur in single mode and then in the dual mode. If you have tested a feature's test configurations covering the 2-way interactions (Pairs) of all the values of all the Test Parameters, you can say that you have done "sufficient enough" testing in most cases.

So for a 2-way (Pairwise) coverage of the example above, the Test Configurations can be reduced from 144 to 13 using the Pairwise Test Case Generator of TestersDesk. Please look at the table in this knowledge link that has a list of test metrics we have gathered to demonstrate the capability of pairwise generator (the "Capability metrics" section at the end of the page).

Isn’t this really an effective way to deal with the exploded number of test cases and tight schedules?And when you want to go for the 3 way or n way coverage, we have other tools as well to serve your various needs.

Happy testing!