In one place I worked
A bad SAP implementation almost destroyed the company. Drained £10 million out of the coffers before they completely restarted. Took another couple of years to get it workable.
In the background was the old 'legacy' system, trundling along with a single guy doing updates for the whole system. Was eventually turned off, for most things, but still runs some others that it's too expensive to get SAP to do.
One of the IT devs who was moved over to SAP basis has a whiteboard that the whole department can see, including directors. He wrote SAP IS SHIT in big black letters. No one has challenged him, and it's still there 18 months later.
As things are today, customers know that a package has been sent out of the warehouse before the business does, as they have received it before SAP has been updated by the external warehousing system, again too expensive on the SAP side to integrate it properly.
SAP, jack of all trades and fecking useless at all of 'em.