Abstract: Virtual testability verification tests play an important role in testability engineering owing to the existence of many difficulties and problems involved in testability prediction and physical testability verification tests. Traditional testability models merely describe the qualitative relationship between faults and tests, while the quantitative characteristics of faults and tests are ill-considered. This leads to large modeling errors which result in inaccurate testability analysis and evaluation results. According to the requirements of the virtual testability verification test, an integrated function-fault-behavior-test-en- vironment model (FFBTEM) is proposed. First, the constituents of the FFBTEM are analyzed and discussed. Then, the mathematical definition and description of the FFBTEM and its submodels are provided. The relationships among the submod- els are established and analyzed. Finally, the FFBTEM is applied to a missile and its test system. The application example indicates that this model is more accurate with the premise of sufficient modeling information, and that it can be applied to testability analysis, virtual experiment and evaluation.

Key words: testability, testability model, testability engineering, testability verification, FFBTEM