A client informed us that they had created (and used) approximately 3,500 test cases to test the search functionality of their application. They had a strong suspicions that (a) they should be able to test the search functionality of their application with fewer tests, (b) the tests they had accidentally omitted tests of many hundreds of plausible combinations of values that would be useful to test for (but did not know how to precisely identify were those gaps were without a huge amount of work), and that (c) many of these tests were quite inefficient in that they repeated many steps that had already been tested in other tests in the plan (even if they were not 100% duplicative of any other single test in the plan).

This client should have spoken to Lanette Creamer before they got into that situation. Lanette is a testing expert and blogger with ideas worth paying attention to. For example, her paper, Reducing Test Case Bloat, is well worth reading as is her blog.

There are times when what you cut may not be bloat. There are some situations where the decisions are the equivalent of “Do we cut off the arm or the head?” Well, a person can live without an arm. If you are in a situation where you are so time constrained that critical areas will be untested, you can still communicate the risk, be transparent and use a strategy to test the most important areas first. It is possible to plan for and do testing for a very time constrained project.


Of course avoiding this situation is best. Improving testing processes to use the best thoughts and tools is a better option. Cutting the bloat can allow resources to be applied to those areas they are really needed. Often though, people are scared of trying new ideas and cling to old methods, even if that results in the organization having to take increased risks by failing to test critical areas sufficiently. They are just more scared of trying new ideas than of getting away with saying we need more funding if you want more testing.

Lanette's article provides 8 specific suggestions for process improvements to reduce bloat. The first suggestion is to use combinatorial testing tools to greatly improve coverage while reducing workload. Another suggestion is to run the bloat reduction ideas by the stakeholders.

As part of your plan to reduce bloat, it can be helpful to state your assumptions about who is important and where you are placing testing priority and why. When reducing test case bloat you are taking a calculated risk. You are weighing the risk of being unable to test new features by insisting on testing every legacy case against the risk of purposefully not running some tests. When you share your starting assumptions with your stakeholders you offer them the chance to counter with their own assumptions and often you can clarify the boundaries of your testing this way to avoid gaps in testing or duplication.


See the full article for more good ideas on how to get better results for the existing testing resources available to your organization.


Related: Design of Experiments is about Learning ASAP and, in Software Testing, Finding Bugs ASAP - Pairwise and Combinatorial Software Testing in Agile Projects - Cem Kaner: Testing Checklists = Good / Testing Scripts = Bad?

By: John Hunter and Justin Hunter on Apr 24, 2013

Categories: Combinatorial Software Testing, Efficiency, Multi-variate Testing, Software Testing, Testing Strategies