Re: That's enough
The rationale of implementing package software applications because you're not in the software development business includes many levers for businesses decisions on the scope of processes and quality of service.
However the inexorable cost pressure means that having decided what to do, the business must accept that how to do it at the cost they are willing to pay is constrained and no longer their decision. If they want free choice away from the reference architecture of their chosen solution there is additional cost. Sooner or later their choices will limit what is affordable and as SAP ECC showed, it's possible to make upgrades and innovation impossible.
Staying on the clean core and deciding only for significant benefits of local innovation requires insight and discipline which some customers will fail to do for their own reasons.
When management Capitalises their project costs they are unwilling to see local developments as a liability rather imagine them an asset. Finance is not the full picture though CFOs like to claim R&D costs back from the tax man. A whole life cycle approach is required to make good decisions.