Re: "Get ready to make processes fit the software"
If you have the 'right' way to do things do all your tools have to be this way?
When you pick a company car do you look at what's on the market and adjust your process for the car you're using, or must it be a 1976 Triumph Stag with 12k on the clock 'cause that is the right one?
SAP is a tool you buy off the shelf, if it's the wrong tool you can buy another or make your own.
If you make it, it'll likely not be as complex, robust or maintainable. If your inflexibility in adapting your processes to new tools is worth that much to you go ahead and spend the time and effort.
Do you see software as a tool, like vehicles or plant, well crafted and artful things at times but tools to serve a purpose, or do you see them as things in themselves which 'must' work in only the way you insist?