Change points estimations of bathtub-shaped hazard functions

杨利霞

Change points estimations of bathtub-shaped hazard functions

The life data analysis has been finding increasing
importance for every industry, resulting in higher quality
and cost reduction in current fierce competitive market.
The hazard function for life models have three distinct
phases of burn-in, useful life and wear-out shown in the
bath-tub curves. Change points estimation is important for
bathtub-shaped hazard function models in reliability and
life data analysis for the product developer and designers to
have a relatively accurate estimation of the burn-in, useful
life and onset of the wear-out life phases. The applications
are for determination and assisting to plan appropriate
burn-in, guarantee, maintenance, repair and replacement
strategies. In this research, life time interval is studied for
bathtub shaped hazard function. Two change points are
calculated for burn-in and useful life phases, as well as
useful life and wear out phases. Two criteria are used in
this study for determination of the change point including
(1) minimum of hazard function and (2) maximum change
in slope of hazard function. This research is structured as a
parametric approach with Bayesian inference utilized as
the parameter estimation. The modified Weibull distribution
are determined as the suitable models for simulation of
all three life phases. In this paper, failure data of an electronic
system case is used for the method demonstration.