a method for determining a recommended maintenance interval for a fleet of units as a function of the operational profile of each unit within the fleet . models are created at the failure mode level for each component of interest . models for all of the individual failure modes are combined to result in an operational metric of interest which a business owning the fleet of units may prefer to hold constant for each unit in the fleet . design evaluation tools may be utilized to evaluate boundaries . a system for determining the recommended maintenance interval .