If you spend more than 20 minutes creating your first canvas you are doing it wrong.

Here’s why…

• Most Plan As don’t work
• It’s very easy to fall into the analysis/paralysis trap and spend a ton of time trying to create that perfect plan.
• It isn’t necessarily starting with a perfect plan, but finding a plan that works before running out of resources.
• In other words: You need to get out of the building.

http://leancanvas.com/blog/lessons/20-minute-challenge.html