Abstract
This paper presents a maintenance policy for a production system to reduce both the environment degradation and the production losses due to failures. To maintain the system, a preventive maintenance action is performed according to statistical knowledge of environment degradation level; while a corrective maintenance action is executed at system failures. Each preventive maintenance action is planned after inspection, which reveals that the value of environment degradation exceeds a specified threshold level. The purpose of this work is to find an optimal vector of inspection times in order to minimize the expected total maintenance and inspection costs per time unit. A mathematical model of the problem is proposed and conditions under which inspection and maintenance dates exist are derived. Numerical examples are given for illustration.