Condition-based Maintenance for Availability Optimization of Production System under Environment Constraints

This paper deals with a condition-based maintenance policy for continuously degrading system to reduce the excessive environment degradation. This maintenance policy consists on maintaining the system with respect to a given threshold level of degradation. Such a level is measured by sequential inspections. According to statistical knowledge of degradation level, a preventive maintenance action is performed on the system, while a corrective maintenance action is executed at system failures. Two kinds of system availability are considered and for each of which a mathematical formulation is given. The objective of the inspection and maintenance policy is to find an optimal vector of inspection times in order to maximize the system availability. On the basis of Nelder-Mead method, an algorithm is implemented to calculate optimum solutions. Numerical experiments are conducted to illustrate the present work.