Skip to main content

The QA Test Matrix

Historically teams I've worked with have taken a few varying approaches when designing tests against acceptance criteria. One is to have the business define the feature, while the team help define the acceptance criteria. Ultimately the business gets the final say if they agree, and further acceptance criteria is either added or removed. The strength of this approach is everyone is involved with the process so nothing is missed or misunderstood. The biggest flaw with this style is that the documentation produced is often verbose, using wordy Given-When-Then scenarios. Using this plan a test plan is then created, mapping tests to acceptance criteria.

An alternative approach is have the business define both the feature and acceptance criteria while the team come up with a corresponding test strategy. This more technical approach allows for a separation of testing activities and test categories. Finally the test plan is replayed back to the business and correlated against acceptance criteria. A negative of this approach is not everyone is involved with the task at the same time. This means there can be some disconnect with what the business is actually asking for. Both approaches work though they can yield mixed results on a case by case basis.

The QA Matrix

I've recently been introduced to the concept of a testing/QA matrix, which is a far more condensed and simplified solution. It has the benefit of the whole team being engaged, while producing nothing more than a simple table that can fit comfortably on a A4 page. The left hand column includes each condition of acceptance, while the other columns should have a mark to indicate the type of test that will cover this functionality. An example is below.

     Unit Integration Acceptance Contract Manual
COA   X
COA           X                             X
COA   X    
...

The beauty of this matrix is that at a glance you can see where you testing efforts lie. If too much occurs on the right of the matrix you may need to re-consider and question your approach. Is there a way to limit the more expensive style of tests and still gain confidence? Other questions can arise around test coverage and whether higher level tests are needed.

When producing this matrix the whole team including the business should be involved. By having everyone together, decisions can be made quickly with everyone in agreement. Additionally it allows debate and discussion around how each feature should be tested.

For higher level tests these can be directly translated into automated tests. While the lower level tests need to confirmed at a later date once the code is complete.

Along side the QA matrix it may be worth while adding a simple diagram of the components that will be involved such as web servers, databases and so on. This can aid discussion and highlight hot spots for changes or tests.

Finally for demonstration to the business the matrix can be used as a form contract for signing off functionality. Once the feature is complete it is simply a case of finding the corresponding tests, confirming their existence and making a note of the commit that included them.

Comments

  1. Hi mate,

    Excellent piece. My only contention is that the matrix is useful in providing an overarching high-level view of the *possible* tests that are determined *at that time* - deeper analysis may result in more tests further down the line, particularly when actually sitting down and pairing to develop the tests (i.e. developing using a test first approach). This means that the matrix will therefore provide an inaccurate reflection of where the coverage lies as the features translate into code.

    However, as an instrument to drive the discussion, I agree, its pretty useful.

    Regards,
    IM

    ReplyDelete
    Replies
    1. Thanks

      Yeah I completely agree, great point. Using the matrix afterwards is really a guide. Additional coverage could easily be added or removed during development. In terms of conversation and discussion around testing approach this has been excellent like you said.

      Delete

Post a Comment

Popular posts from this blog

Constant Object Anti Pattern

Most constants are used to remove magic numbers or variables that lack context. A classic example would be code littered with the number 7. What does this refer to exactly? If this was replaced with DaysInWeek or similar, much clarity is provided. You can determine that code performing offsets would be adding days, rather than a mysterious number seven.Sadly a common pattern which uses constants is the use of a single constant file or object. The beauty of constants is clarity, and the obvious fact such variables are fixed. When a constant container is used, constants are simply lumped together. These can grow in size and often become a dumping ground for all values within the application.A disadvantage of this pattern is the actual value is hidden. While a friendly variable name is great, there will come a time where you will want to know the actual value. This forces you to navigate, if only to peek at the value within the constant object. A solution is to simple perform a refactor …

Three Steps to Code Quality via TDD

Common complaints and problems that I've both encountered and hear other developers raise when it comes to the practice of Test Driven Development are: Impossible to refactor without all the tests breakingMinor changes require hours of changes to test codeTest setup is huge, slow to write and difficult to understandThe use of test doubles (mocks, stubs and fakes is confusing)Over the next three posts I will demonstrate three easy steps that can resolve the problems above. In turn this will allow developers to gain one of the benefits that TDD promises - the ability to refactor your code mercifully in order to improve code quality.StepsStop Making Everything PublicLimit the Amount of Dependencies you Use A Unit is Not Always a Method or ClassCode quality is a tricky subject and highly subjective, however if you follow the three guidelines above you should have the ability to radically change implementation details and therefore improve code quality when needed.

DRY vs DAMP in Tests

In the previous post I mentioned that duplication in tests is not always bad. Sometimes duplication becomes a problem. Tests can become large or virtually identically excluding a few lines. Changes to these tests can take a while and increase the maintenance overhead. At this point, DRY violations need to be resolved.SolutionsTest HelpersA common solution is to extract common functionality into setup methods or other helper utilities. While this will remove and reduce duplication this can make tests a bit harder to read as the test is now split amongst unrelated components. There is a limit to how useful such extractions can help as each test may need to do something slightly differently.DAMP - Descriptive and Meaningful PhrasesDescriptive and Meaningful Phrases is the alter ego of DRY. DAMP tests often use the builder pattern to construct the System Under Test. This allows calls to be chained in a fluent API style, similar to the Page Object Pattern. Internally the implementation wil…