Test case generation for Function Block Diagram based on blocks’ predefined behaviour

Automatic test case generation based on knowledge of a model is currently a challenge for many researchers and developers. This article describes the first of two complementary methods for test case generation for Function Block Diagram (FBD) models and grey-box testing. The first method utilises predefined tested behaviour (unit tests) of each used Function Block and combines them together. This method adds a structural limitation to the model. Therefore, the model needs to be split into multiple parts and processed per partes. The second method is then used for a combination of these partial results. Together these two methods can generate test cases even for models that include feedbacks, internal states, and traffic delays.