The System Reliability Analysis Of TTT And Optimal Maintenance Strategy

The reliability, has the close relation to the working life of people and the economic benefits of the factory, so the reliability of the system get people’s more and more attention in the actual production life and maintenance.This paper is divided into two parts.In the first part, the total time on test (TTT) is well-known due to its striking applications to different areas of science. On the basis of the strategy about the age replacement, some different life distributions such as Weibull distribution and Exponential distribution are considered and a multi-objective optimization model of the preventive maintenance cycle is constructed with the two indexes, average expected cost and average availability of the system. The emphasis is that the multi-objective optimization model is solved accurately by means of the TTT transformation function, the preventive cycle is determined and the maintenance strategy is given under the different cases of discount rate. Then an objective optimization model of preventive maintenance cycle is also constructed with the state probability of the spare parts in fault. Some numerical examples are also included to illustrate the decision-making process and to verify its effectiveness.In the second part, on the basis of the strategy about age replacement, a multi-objective optimization model of preventive maintenance cycle is constructed with two indexes, average expected cost and average availability of complex compound systems. The emphasis is that the multi-objective optimization model is solved accurately by means of TTT transformation function, then the preventive cycle of compound systems is determined. In the complex compound systems, the reliability simulation problems is researched by using Monte Carlo method to establish stochastic model. Under the assumption, the problems are studied based on progressive Type-Ⅱ censoring with random removals by using Bayes and MLE approaches. Under the squared loss, the formulae are given to calculate Empirical Bayes(EB) estimation of the failure rate, the reliability function and mean lifetime for system. The modern electronic products and the mechanical engineering system are too complicated. According to the redundancy problems in the complex compound system, we analyse the redundancy of constraint conditions, and the redundancy optimization nonlinear programming model of the system reliability distribution is established based on MATLAB and LINGO software. Then we give the ideas on solving the problem. The optimization model is given which provides the integer optimization method of the reliability for the reliability engineering. Finally, the optimization results of the example system show the effectiveness and applicability of both methods respectively by comparison.