Software today is getting more and more complex. This complexity brings fresh challenges in testing the software UI and its underlying functionality. Test engineers have to worry about a lot of different kinds of software controls, interfaces between software modules, etc. Test engineers find some software modules easier to test than others. These test modules have "testability" built into them which helps the test engineers make better test cases faster, tests that are easier to automate and hence have better chances of catching bugs in the code.

This paper defines testability and discusses its importance for software applications. We take a look at why it gets left out of most software components and why it needs to be there right at the design stage of the software development life cycle. It also examines common software controls from a testability point of view and suggests improvements that should be made to ensure better testability.