Parent/Child Assets

Hi,
My requirement is that:

If any adjustments are done to an asset, the adjustment should have its own life rather than the original asset's life and this was for the Tax purposes. This was taken care by setting up the parent/child relationship in the corp book and it did the job in the tax book too.

But now we need the parent/child relationship only for the tax book and not for the corp book( The adjustments should take the life of the parent) . How should i do that....Any suggestions/help on this would be appreciated.

Thanks in advance.