A Bayesian semiparametric proportional hazards model is presented to describe the failure behavior of machine tools. The semiparametric setup is introduced using a mixture of Dirichlet processes prior. A Bayesian analysis is performed on real machine tool failure data using the semiparametric setup, and development of optimal replacement strategies are discussed. The results of the semiparametr...

In this paper we survey existing results concerning the joint distribution of the sequence of estimates of the parameter vector when a model is tted to accumulating data and we provide a uniied theory which explains the \independent increments" structure commonly seen in group sequential test statistics. Our theory covers normal linear models, including the case of correlated observations, and ...