The estimated lifetime of a piece of equipment can be defined in one or more of the following three places:
In the definition of the Device type
In the definition of the Device subtype
In the definition of the Model
Each estimated lifetime definition is inherited by the definitions that follow unless a new value is entered.
For example, if you define the estimated lifetime of a device type as 24 months, the estimated lifetimes of all device subtypes associated with that device type default to 24 months. Likewise, the estimated lifetimes of all models associated with those device subtypes also default to 24 months. If however, you change the estimated lifetime to 18 months in the definition of the device subtype, the estimated lifetimes of all models associated with that device subtype default to 18 months.