Multi-state system test modeling and test point selection method

Abstract:

To solve the test problem of degradation state in testability design, this paper proposes a multi-state system test modeling and test point selection method based on structure and function. Firstly, considering the description of performance states in multi-state system, the general idea of multi-state system test modeling based on structure and function was defined, and the related descriptions of structure, function, and test in the model were analyzed. Secondly, the problem of state testing was discussed, and the calculation methods for the state sets that can be detected by a single test or by a combination of test sets were analyzed. In addition, the state detection rate was proposed to quantify the test indexes of the system states. Finally, given that the fault testability problem is included in system testability design and analysis, a test point selection method of multi-state system integrating fault detection rate, fault isolation rate, and state detection rate was proposed under test cost constraint. Results show that the multi-state system test modeling method could analyze the testability of fault as well as the testability of degraded state. Compared with that obtained by the test selection method of binary system, the optimal test set obtained by the test selection method of multi-state system achieved higher state detection rate under test cost limitation. In the case of unlimited test cost, the optimal test set obtained by the test selection method of multi-state system not only achieved higher state detection rate, but also obtained the same maximum fault detection rate and fault isolation rate as those of binary system.