Are your asset management models your acquistion models?

Pretty basic question.

How do your firms track the financial returns of your investments quarter to quarter (or whatever periodic basis, if you track at all)?

At my shop we take our acquisition model and manually input historicals and re-project assumptions going forward. However, my bosses love to make my team manipulate the model with various inputs and assumptions that change weekly/monthly. So as a result the models becoming a living nightmare to work with and become a "hot potato" where folks had forgotten the logic/reasoning behind manual entries and don't understand what someone had done previously in the model.

I guess I've only been at one operator/developer, so I don't know if this is standard or if this a problem unique to us.