For the aero mechanical system, the combination of high engine life-cycle costs, concerns for greater safety and changing operational demands create the need for improved engine health management. Engine health management represents the largest part of overall aircraft maintenance costs and, due to safety considerations tends to be performed conservatively. This talk represents how to predict, detect and conduct pre-emptive analysis of adverse trends of engine system by engine trending and diagnostics. Also speaker introduces how to reduce shop flow days, improve reliability by phasing out time-based removals and increasing MTBR, and reduce life cycle costs using reliability-centered maintenance. For better understanding, this tutorial presents several engineering cases which are steam turbine rotor system diagnostics, wind turbine system diagnostics and so on. At the end of speech, this talk gives an insight of the quinary industry with health management.