Depreciation of Compound Assets
Although the components depreciate together with the compound asset, they're treated as individual assets. Each component has its own depreciation history record. The compound asset record shows the total component depreciation, including alternate depreciation, but it won't have journal entries. You can find the journal entries in the component asset record under Components > Depreciation History subtab.
The compound asset's depreciation start date follows the date of the component with the earliest depreciation start date. The end date follows the date of the component with the latest depreciation end date.
For more information about depreciating an asset, see Asset Depreciation.