When launching a new project or initiative, I often think about it as a giant boulder sitting in a field. The goal is to roll the boulder.
No matter how you go about it, there's going to be a lot of pushing, a lot of hard labor. You can't avoid that.
But if you start pushing the boulder first, you're going to end up putting in a ton of effort without a lot of result. The boulder is still too rough and lopsided. The ground is uneven and the landscape unknown.
It can take a LOT of discussion and planning — defining and refining — to smooth out that boulder and prepare a clear path. A lot of energy to get team members to push from the same direction. But then, when you start pushing, the labor is worth it — you move, you pick up momentum, the ongoing work to roll the boulder is much more sustainable.
Now, obviously, in real life things are rarely so linear. Often it's necessary to start pushing before everything is neatly prepared. And gaining momentum might bring up rough spots you hadn't noticed before. You're probably rolling multiple boulders at once.
But don't neglect shaping the boulder. Don't neglect preparing the path. The combination of all three (pushing, shaping, preparing) is what makes new ideas successful.