Gray box testing is a software testing technique that uses a combination of black box testing and white box testing. Gray box testing is not black box testing, because the tester does know some of the internal workings of the software under test.
The current implementation of the Gray box methodology is heavily dependent on the use of a host platform debugger to execute and validate the software under test. The Gray box toolset can now be called upon to perform and verify performance requirements. It is now possible to verify/validate CSCI/CSU/Module/Path timing, functional and structural requirements in a single test case with the same format used to verify/validate functional requirements.
Gray box Software testing in Real-Time seeks to provide a method of testing software that will be both easy to implement and understand using Commercial off the Shelf (COTS) software and hardware. The original Gray box methodology did not address real-time or system level testing. The major concentration of the methodology was to provide a system that allowed test engineers to create ample test suites that thoroughly tested a software product.
The Gray box methodology utilizes automated software testing tools to facilitate the generation of test unique software. In gray box testing, just as in black box testing, tester test from outside of a product, just as he do with black box, but tester make better-informed testing choices as tester know how the underlying software components operate and interact.
An example of Gray Box Testing would be when the codes for two units/modules are studied (White Box Testing method) for designing test cases and actual tests are conducted using the exposed interfaces (Black Box Testing method). Though Gray Box Testing method may be used in other levels of testing, it is primarily useful in Integration Testing.
