A Combinatorial Test Suite Generator for Gray-Box Testing

In black-box testing, the system being tested is typically characterized as a number of inputs, where each input can take one of a number of values. Thus each test is a vector of input settings, and the set of possible tests is an N dimensional space, where N is the number of inputs. For example, an instance of a simulation of a crew exploration vehicle's (CEV) launch pad abort scenario can have 76 floating-point inputs. Unfortunately, for such a large number of inputs only a small percentage of the test space can be actually tested. This paper characterizes levels of partial test space coverage and presents Testgen, a tool for generating a suite of tests that guarantees a level of test space coverage, which a user can adapt to take advantage of knowledge of system internals. This ability to adapt coverage makes Testgen a gray-box testing tool.