Sub-asset doesnt inherint the books from the parent asset!??

Dear SAP Experts:

At our system, Depreciation areas in asset master data is determined based on a custom table. This custom table logic is as the following: Based on the asset class, Company code, and asset category, the Deprecaition areas, depreciation key, and useful life will be determined.

For example, if Asset Class is FA50, CoCd 1000, and XXXX is asset category, the following will be determined: z111 Dep Key, 40 Years useful life, and Depreciation Area (1,10,12,14) will be there but Depreciation Area 15 is there too but with de-activated check box. So for this particular asset will have 1,10,12, and 14 books with activated indicator, and at the same time book 15 will also show in the master data but with as deactivated indicator.

However we have created sub-asset for the above mentioned asset in the example, but we found that this asset doesnt look at the custom table, and the depreciation areas are determined based on the asset class, in our case, all the books are there. Our target was to have the Sub assets as the parent asset in terms of books.

We have tried to de-activate Depreciation area manulaly in the asset master, but this resulted loosing the depreciation area completely as opposed to having the asset with de-activated indicator as in the parent asset.

The only reason of having this custom table is to comply with the asset classes for the corporate, and they dont want want to add any additional asset classes

The problem that we faced in this scenario that the sub asset doesnt have book 15 or having it as activated, and this cause errors upon settleing dollars from AUC to the sub asset. The error that we get is regarding inconsistency in between the sub asset books and the AUC books..

Experts: is there any to have the sub assets to inherint the same books as the parent assets??

Regards

Ahmeda