Author(s)

I. Žutautaitė-Šeputienė, J. Augutis & E. Ušpuras

Abstract

This study presents the developed algorithm for assessment and updating estimates of the parameters in mathematical models of device or systems ageing process (that is characterized by increasing failure rate) with respect to prior information and obtained observations (failure data). The proposed algorithm is based on a modified application of the Bayesian approach (BA). In the paper some ways for the forecasting of residual lifetime with respect of allowed risk margins using obtained updated mathematical model of increasing failure rate are presented. Keywords: degradation, ageing, increasing failure rate, Bayesian approach. 1 Introduction In this research work mathematical models of complex devices or system ageing (or degradation) processes are analyzed. In engineering, ageing is understood as a process during which characteristics (physical, mechanical or chemical properties) of systems, structures or components are changing in time, i.e., technical devices lose the ability to perform their designed functions (dependability of devices is decreasing). In order to avoid problems during device operation time it is important to evaluate the effect of the ageing phenomena. Therefore mathematical models that describe the ageing phenomena are necessary. Contribution of a probabilistic assessment of the ageing process is significant to strategic planning of devices control. Performing a reliability analysis, it is important to not only test whether the current condition of device corresponds to the safety requirements (such as that denoted by technical specifications or regulatory institutions) but also to evaluate residual lifetime

Keywords

degradation, ageing, increasing failure rate, Bayesian approach