To echo this point: in my experience, a lot of businesses seem to believe that their internal processes are unique for a reason and offer some competitive advantage instead of being that way because somebody made a decision years ago and that decision stuck.

The more you customize your ERP, the worse off you are. The fastest, cheapest code is the code that's not written in the first place. The maintenance cost and difficulty upgrading down the road are many multiples of the sunk cost.