Depreciation Lives for Leasehold Improvements

Hi-

We're in the process of bringing up our first location on 11i and we have a large amount of Leasehold Improvement assets.  As the LHI assets are depreciated over the remaining length of the building leases..and have different in-service dates, the remaining depreciation periods are all different.  We're trying to determine the best way to ensure depreciation is calculated correctly for each asset.  The first recommendation was to define a separate asset category for each LHI - - - but I'm hoping there is another, cleaner, alternative.

Thank you-