PSI - Issue 20

V.I. Kuksova / Procedia Structural Integrity 20 (2019) 98–102 V.I. Kuksova / Structural Integrity Procedia 00 (2019) 000 – 000

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technical condition of OD. 3. The conditional probability of the undetected refusal – probability of that: a faulty (disabled) object as a result of diagnosing is recognized as properly functioning (efficient); in the presence of refusal (malfunction) as a result of diagnosing the decision on lack of refusal (malfunction) in the element of OD is made. 4. The conditional probability of the false refusal – probability of that: a properly functioning (efficient) object as a result of diagnosing is recognized as faulty (disabled); in the absence of refusal (malfunction) as a result of diagnosing the decision on existence of refusal (malfunction) in the element of OD is made. 5. The accuracy of diagnosing is characterized by compliance of results of the diagnosis to real indexes. It’s estimated with the help: a mean square deviation of the predicted parameter of technical condition of OD for the considered time period; a mean square deviation of the predicted OD residual resource; a probability of no-failure operation of OD, indexes of change of the predicted diagnostic parameter; a fiducial probability of the received diagnosis (the lower bound of probability of no-failure of OD in safety parameters for the considered time period). 6. The completeness of technical diagnosing. It can be determined by the relation of number of the parameters, captured by monitoring, to total number of the parameters, defining operability of an object. 7. The depth of searching of the place of refusal (malfunction) – the characteristic, set by the indication of a constituent of an object, with an accuracy to which the refusal (malfunction) is located. 8. The anticipation interval – the estimated time before the predicted refusal of OD, allowing to define the maintenance moment to avoid refusals and accidents. 9. The safety and resistance of STD to influence of the damaging factors of an emergency. 10. Technical and economic characteristics of diagnosing: cost per unit of diagnosing; average operational labor input of diagnosing; average operational duration of diagnosing; frequency of diagnosing. 11. Information indexes of quality of diagnosing and information value of results of diagnostics. 3. Cost efficiency of STD In practice they usually calculate (taking into account branch features of OD) the cost efficiency of STD and various indexes characterizing quality (target effectiveness) of technical diagnosing. The cost efficiency of STD is defined by comparison of expenses on creation, equipment, maintenance and development of STD with the received economy from results of its functioning. Economy from results of functioning of STD consists of two main components: economy of the current expenses on OD from implementation of STD; sum of losses, prevented from reducing accident rates OD. Depending on branch specifics of OD, the savings of the current expenses from the implementation of the STD can be formed by the following articles: