In this paper, we consider a Bayesian dynamic forecasting model that u
tilizes both the engineering knowledge about the product reliability a
nd attributes (success or failure) data gathered from the inspection o
f the early stage of development or storage. We assume that a prior di
stribution of reliability follows a beta distribution. The expected re
liability is represented as a cumulative logistic function of the leng
th of time that a new product has been under development or a finished
item has been stockpiled in storage. As periodic testing produces att
ribute data, a prior distribution is updated. The expected reliability
and forecasting errors are obtained from a posterior distribution tha
t reflects the uncertainty involved in forecasting. The proposed metho
d is applied to predict the expected reliability decay of a gyroscope
in a missile stockpile. (C) 1997 Elsevier Science Ltd.