A model for functional test generation and testability analysis

An overview has been given of a new approach to functional test generation. The program GESTE permits the generation of symbolic tests by constructing a path through the graph model, establishing, and solving a system of equations and inequalities. The model extracted from a behavioural VHDL description contains control flow and, implicitly, data flow. The behavioural level fault model includes both faults in the data part and faults in the control part. A new method of testability analysis considers functional and structural aspects of the model. By means of a preference relation a decision is based on the multi-criteria controllability and observability measures. This testability analysis is used to select the best path for generating a test. The test generation program GESTE is under development. First results show that the method offers a promising way to generate symbolic tests