Software Quality

Black-box vs. White-box Testing

Choosing the Right Approach to Deliver Quality Applications

OVERVIEW Within the automated testing world there are two predominate testing methodologies: black-box and whitebox. This paper seeks to explore the pros and cons of both approaches and to identify when each approach should be used to ensure quality applications are delivered to market. In the end, this paper concludes that while black-box testing has had its drawbacks in the past, innovative approaches to black-box testing make it the likely choice to deal with the ever increasing complexity of applications and delivers lower Total Cost of Ownership (TCO) and a better Return on Investment (ROI) to organizations. DEFINITIONS Black-box: This testing methodology looks at what are the available inputs for an application and what the expected outputs are that should result from each input. It is not concerned with the inner workings of the application, the process that the application undertakes to achieve a particular output or any other internal aspect of the application that may be involved in the transformation of an input into an output. Most black-box testing tools employ either coordinate based interaction with the applications graphical user interface (GUI) or image recognition. An example of a black-box system would be a search engine. You enter text that you want to search for in the search bar, press “Search” and results are returned to you. In such a case, you do not know or see the specific process that is being employed to obtain your search results, you simply see that you provide an input – a search term – and you receive an output – your search results. White-box: This testing methodology looks under the covers and into the subsystem of an application. Whereas black-box testing concerns itself exclusively with the inputs and outputs of an application, whitebox testing enables you to see what is happening inside the application. Whitebox testing provides a...