Model of conjoint fault detection at metrological service of electronics

Three types of conjoint fault detection are usually employed at the diagnostic of electronic systems, namely: independent conjoint fault detection, compatible conjoint fault detection, and zone conjoint fault detection. We have performed comparative consideration of the employment of these three types of conjoint fault detections for the troubleshooting of electronic systems. Expressions for quantitative assessment of quality indices (average recovery time, mathematical expectation of deviation of a diagnosis with one error in evaluation of the inspection result, the probability of correct diagnosis and the probability of correct evaluation of the result of the test) for all three types of conjoint fault detections are derived. Basing on these expressions a generalized model, which combines all three types of conjoint fault detection and performs a selection of the most appropriate type of conjoint fault detection, is developed. The model is capable of predicting quantitative parameters of the quality of diagnostic procedure with the account for the metrological reliability of measuring instruments. The latter allows for lowering of the labor expenses at repairing of the electronic systems. The model is also designed for the account of a possible diagnosis mistake for three types of conjoint fault detections. In the final stage of the model, a conditional diagnostic algorithm is developed and qualitative indicators are specified.