Every business software is at least as complex as the business process it models. That's the thing you training for.

Every detail of the business process is now explicit. Employees have to be forced to work according to actual process. You need quite a bunch training for that. Then employees will find shortcuts to make their own job a bit faster/easier, which will fuck up some cases. You need even more training for that and possibly some redesigns. And all you get from that is depression