Abstract: A model for built-in test (BIT) integrated expression is presented based on the composition analysis of its main design elements. Mathematical definitions of the model are established, including the BIT unit model, the set of BIT hierarchy relations, the set of BIT data transmission modes, the set of BIT execution orders and the model for BIT integrated expression. A block diagram model and a table model for the BIT integrated expression are also proposed based on the mathematical definitions, and these two models can be directly used in engineering analysis. Finally, the model for BIT integrated expression is applied to the case of an aided navigation system. Both the block diagram model result and the table model result are provided, which serve to show the availability and validity of the model.

Key words: testability, built-in test, design, integrated expression, model