Kai Yao - Department of Mathematical Sciences, Tsinghua University, Beijing ۱۰۰۰۸۴, China
Dan A. Ralescu - Department of Mathematical Sciences, University of Cincinnati, Cincinnati, OH ۴۵۲۲۱-۰۰۲۵, USA

Age replacement policy is concerned with finding an optional time tominimize the cost, at which time the unit is replaced even if itdoes not fail. So far, age replacement policy involving random agehas been proposed. This paper will assume the age of the unit is anuncertain variable, and find the optimal time to replace the unit.

Uncertainty theory, Renewal process, Age replacement, Maintenance