Abstract
In the statistical analysis of the field life data, we must sometimes estimate the failure rate of each component of a system by the system life data. In this paper a competing risks model has been used for determining the lifetimes of the components and two types of incomplete life data are considered. Assuming that the lifetimes of the components are independent and exponentially distributed variates, the maximum likelihood estimators or the uniformly minimum variance unbiased estimators for the failure rate of a particular component are derived, and the efficiencies of these estimators are also discussed. The analysis shows that when the ratio of the failure rate of the particular component and that of the other component, say ρ=λ/μ, is large, the reduction in efficiencies of estimators obtained by using the incomplete system life data is not so much as compared to that obtained by using the complete data.
