How do I create a risk-based testing plan that focuses more coverage on higher priority areas?
This lesson describes how you can use Hexawise's "Mixed-strength interactions" test generation feature to create risk-based tests.
Hexawise allows you to adjust testing coverage to focus more thorough coverage on selected, high-priority areas
One straightforward risk-based testing technique is to simply enter a specific value multiple times in the "Inputs" screen. Entering "Male, Male, Female, Male" as Values, for example, would result in "Male" appearing three times as often as "Female."
A more powerful risk-based testing strategy is generating Multi-Strength test sets, as described in the following example. This feature can be helpful to use in many (if not most) of the plans you will create.
Let's set the context and the problem we're trying to address
We have a mission-critical application that includes several large changes in this release. We've filled in our inputs for our System Under Test, and we see that a 2-way solution based on our test inputs would require 84 tests.
Curious to see how many tests would be needed for a more thorough test plan? Generate a set of 3-way tests! Unfortunately, this more-thorough solution requires almost 4 times as many tests. Ugh! We don't have time all of those!
Determine what Values we want to devote more thorough testing
What we want to do now is to generate a set of tests that will focus extra coverage on the high-priority sets of values below, while maintaining pairwise coverage for every Value in our plan. Creating a "Mixed-strength" plan will allow us to do exactly that!
Select "Mixed-strength interactions" from the drop down list next to the plan name, on the "Test Cases" screen
Next, identify at least 3 columns of Values which you would like to receive extra thorough coverage. Click on "Reapply" to generate a new set of tests
Comprehensive coverage for all Values in those 3 columns is achieved with one another AND achieves 2-way coverage of all the possible pairs of Values
Another way to look at the set of Risk Based Tests tests that we have just created is to imagine temporarily removing everything from our plan except for the Values from the high priority Parameters...
Simple math tells us that to test every possible combination involving all of the 3 sets of high priority Values requires 3×5×8 = 120 tests. All 120 of these 3-way combinations are included in the 120 Mixed Strength ("Risk-Based Testing") tests that we created...
In addition to achieving comprehensive 3-way coverage of the high priority Values we identified, the 120 Mixed-strength tests we created ALSO made sure that we tested every single pair of Values together in at least one test case
The Hexawise test generation algorithm is able to achieve both of these objectives in only 120 tests
As shown in the two screenshot images above, we can see that it takes 120 tests to achieve 3-way coverage of all of the possible combinations of the 3 sets of high priority values and that it takes 84 tests to achieve 2-way coverage of all of the Values in the plan. In this example, the Hexawise test generation algorithm identified a way to combine both of these objectives into only 120 Risk-Based Tests.
In short, even after focusing additional thoroughness on our three highest priority sets of values, we generated a solution with only 120 Mixed-strength tests (versus almost 3 times that many in the unweighted 3-way coverage option). We were able to focus the additional coverage where we wanted it without generating lots of additional tests that we do not have time to execute.