RELIABILITY STUDY OF AN INTELLIGENT TRANSMITTER

An intelligent transmitter reliability study has to deal with several issues: various interactions between both material elements and functions; behaviors of components as programmable units and software which are difficult to predict when faults or failures occur, as well as the consequences on functions processing. A “3-step model” is therefore proposed to include both functional and material aspects, using Goal Tree–Success Tree (GTST), and setting faults and failures as a third full part. Then, Master Logic Diagrams (MLD) aim to represent several types of relationships between faults or failures, material elements, and functions. Probabilities are used for MLD components to take the indeterminate relationships into account. Quantitative assessments are then performed, using an infrared gas transmitter as an example: total relationships between any fault or failure and any function, probabilities of malfunction and failure modes. Moreover, uncertainty analyses show that even if input relationship data are uncertain, precise results can be obtained. These properties make the proposed model especially suitable for evaluating the reliability of intelligent transmitters. Finally, some design issues are discussed, taking advantage of the proposed model.