ESTIMATION OF A COMPOSITE HAZARD RATE MODEL

The increasing hazard rate model is widely used in estimating reliabil ity of mechanical items. The common life distributions such as Weibul, normal, and log-normal allow for strictly increasing hazard rates. In this paper we propose a composite hazard rate model which is constant over a period of unknown duration, and then strictly increases after the threshold value. In reliability engineering graphical regression m ethods are used to estimate unknown parameters. We investigate the per formance of two such estimators. Comparisons are made using Monte Carl o simulation. Applications of some real world problems are given.