in my Scrum classes I warn attendees of what I call the Scrum Promise: If you adopt Scrum, there will be a day you come into the office nearly in tears over how hard the change can be. This is because Scrum doesn’t solve problems, it uncovers them and puts them in our face. Then, through hard work we address them.
This is very like the description of Kanban that Mike Rother offers in Toyota Kata – your first attempt at Kanban will crash and burn, and it’s from the ashes that you will build a better process.
Keep in mind, by the way, that the kanban system does not cause problems, it only reveals them
Mike Rother: Toyota Kata
Lean thinking means fixing problems when they are identified.