Maintenance policies for intermittently-used systems

Abstract

Four types of maintenance policies for intermittently-used systems are studied. The usual models of age, periodic, and block replacement, and coordination of maintenances for a group of machines are modified into the case of intermittent use. The system is used when a need occurs and then idle for some time. Since the system is intermittently used, our policies are based on the number of uses or cummulative use-time and preventive maintenance actions are scheduled at system idle time. The time duration of uses are assumed i.i.d. random variables. The replacement time and system idle time are also assumed zero. The average cost rates of each model are obtained and the optimal numbers or optimal cummulative use-times which minimize the average cost rates are explored. Exponential duration of a use and Weibull or Erlangian TTF are assumed. Numerical examples for each model are given.