Reliability Measures Analysis of Multi State Systems under Rework Policy

Abstract

The reliability has a progressive prominence in each and every field of science due to an on-going process of degradation in a system or sub-system. Degradation in a system possessed by the several failures. Failures occur in the system due to the interaction among the components or caused by adverse environmental condition that affect the parameters of system effectiveness. Reliability theory has a wide application such as manufacturing company, electronic products, power plants etc. In modern scenario, reliability evaluation is an important aspect in designing, and safety from fault detection point of view in the complex repairable system. This work develops the concept of fault coverage technique to improve the reliability of the fault tolerant industrial system by reducing the chance of system failure through covered fault as soon as possible after detection. To a large extent, the performance of the system to be depends upon its maintenance in addition to reliability. Maintenance of the system leads the notion of two different types of repair between two adjacent transition states, which seems to be possible in many engineering systems. When this possibility exists, reliability of the system can be analyzed with the help of Gumbel-Hougaard family copula. In this thesis, the reliability measures are examined by using both the approaches fault coverage and Gumbel-Hougaard family of copula simultaneously. newlineThe entire work of this thesis subjected to the performance analysis of various complex industrial systems such as CNC machine, water cooling system, thermal power plant, carburettor, wind power plant and two general structures of complex systems consists of single unit and n units respectively. These systems are modelled by employing the Markov process and supplementary variable technique and derived the explicit expression for the state transition probabilities and reliability measures such as availability, reliability, mean time to failure and mean time between failures. The investigation of the performance