The variability in age between the youngest phase and the oldest phase in a phased development.
There are essentially two classes of dispersion:
- Narrow: If
the variability is narrow (say 2-3 years) then it may be appropriate to
average the age of all the phases and use this blended age for all
- Wide: However, if there is a wide dispersion between the youngest and
oldest phases (say 4-8 years) then it may be necessary to prepare a
separate asset inventory for each phase