Getting the users in the org to, you know, actually use that well-specced, well-built project, which was delivered within time and budget (or with only a small overrun). I mean, use it at all, or use it enough for it to deliver its benefits. Real life issue. Seen it on at least a few projects I've worked on, including two early in my career. Inertia, luddite fears, turf wars can be some of the causes.