I think a key here is making sure those people talk to everyone who uses the current solution, not just the executives. They need to understand the actual use cases and pain points of the day to day, not just what the executives think it is.

Where I’m at we brought some software in-house and that part was skipped, or ignored. Years later, in talking with the lead on that project, he will admit that was a big miss. On the one had, to make change he didn’t want to be tied down and pushed around by past politics and issues, but on the other hand, some big fundamental problems were carried forward from the old solution to the new, and there was no way to really fix them after the fact, without effectively starting over.