A few years ago, I was part of an amazing implementation team -- we implemented more meaningful change in less time, than I ever thought possible. We identified issues (or were presented problems by users), prioritized them (don't skip this step), defined solutions, received approval, and implemented the approved solutions -- all was right with the world.
Then there was a disturbance in the force. We lost a team-member, who was of course, summarily replaced. The new team-member was affable and capable, they just had one proverbial fatal flaw. A flaw it took months to identify, and by then it was too late, we'd achieved stagnation, and lost team-members to more promising projects...
The fatal flaw was simple, Great was never Good enough!
It has been said, Good is the enemy of Great! This is the mantra of organizational changologists everywhere -- yep, I just made that word up. What is often forgotten by these agents of change is Perfect is the enemy of Great!
What will always ever be true is there is no such thing as a PERFECT system. If you want to be effective implementing change, it is absolutely critical to maintain the discipline to deliver on good enough.
If you find yourself in the midst of a stalled implementation, take a look at what you're trying to deliver. Is pursuit of perfection the problem; if so, act quickly to determine what good enough is, before the pursuit of perfection ends in project failure.
It took a bit of doing, and a couple of years, but we managed to put the band back together. Good team-members with great chemistry still require a healthy environment to thrive. Projects stagnated or floundering because of poor decisions or unreasonable expectations are not healthy environments.