Abstractions for Model-Based Testing

The idea of model-based testing is to compare the I/O behavior of an explicit behavior model with that of a system under test. This requires the model to be valid. If the model is a simplification of the SUT, then it is easier to check the model and use it for subsequent test case generation than to directly check the SUT. In this case, the different levels of abstraction must be bridged. Not surprisingly, experience shows that choosing the right level of abstraction is crucial to the success of model-based testing. We argue that models for specification purposes, models for test generation, and models for full code generation are likely to be different. The paper classifies and discusses different abstractions. It is intended as a step towards guidelines for those who build behavior models to the end of testing.