Optimal Apparoch for Replacement Intervals of Warm Standby System

The protection device with low price and high maintenance cost can be used for a long time.In order to improve availability of protection system,a method of increasing redundancy and periodic replacement is proposed.Firstly,the equivalent model of cumulative failure probability was established.Then,the wasting time of the spare part is converted into the working time of the using part.Considering the optimization objective,under the strategy of block replacement,the availability model in infinite period with the maximum availability and the cost model in finite period with the minimum cost are established separately.In this case,we seek out the optimum replacement interval and verify the applicability and validity of the model through contrast and analysis.Finally,the paper gives a brief discussion of future research area about warm standby system maintenance.

Availability and cost-benefit evaluation for a repairable retrial system with warm standbys and priority

This paper investigates a warm standby repairable retrial system with two types of components and a single reparman,where type 1 components have priority over type 2 in use.Failure and repair times for each type of component are assumed to be exponential distributions.The retrial feature is considered and the retrial time of each failed component is exponentially distributed.By using Markov process theory and matrix analytic method,the system steady-state probabil-ities are derived,and the system steady-state availability and some steady-state performance indices are obtained.Using the Bayesian approach,the system parameters can be estimated.The cost-benefit ratio function of the system is constructed based on the failed components and repairman's states.Numerical experiments are given to evaluate the effect of each parameter on the system steady-state availability and optimize the system cost-benefit ratio with repair rate as a decision variable.