cost benefit analysis for turbines

A wind farm has 100 wind turbines that are expected to work for 20 years. The wind farm owner would like to see if it is worthwhile to install a condition monitoring system (CMS) to detect wind turbine failures for each wind turbine in the farm, as CMS for wind turbines is quite expensive. If a failure is successfully detected by CMS at an early damage stage, the maintenance cost for this failure
can be substantially reduced. However, the CMS will not be able detect all failures. Thus, the detectability of CMS for certain wind turbine failure mode should be modeled probabilistically as Dt ,namely “probability of detection”.
how to carry out a cost benefit analysis to help the wind farm owner make the decision using the reliability theory considering different wind turbine failure models