Investment in monitoring systems can be used towards the reduction of the maintenance cost of modem plants. Sensors and instrumentation, which record variables describing performance, vibrations, and other process parameters, have granted new opportunities in the design of trend-monitoring systems. These systems can be used toward scheduling of maintenance without impacting planned production schedules. Further, by monitoring these variables to provide information about the changing life expectancy, maintenance engineers can base service on actual field conditions, rather than relying solely on standard machine life estimates. Moreover, these systems can increase the overall efficiency by reducing energy consumption.