The term “concrete head’ is the result of a Japanese translation. A concrete head is someone who is resistant to the changes that Lean brings. Obviously this is a derogatory term. I like the image for someone who doesn’t want to get it. But remember concrete takes a while to set-up. Don’t give up too soon.
Implementing Lean Thinking can have a revolutionary effect, but not always one that is positive. At some point in just about every revolution, the dynamic comes into play of, “You’re either for us or against us.” This is when you can lose a lot of good people.
One of the reasons you spent so much time and effort building high-performing teams is to better face the reality that some people get it, some people don’t get it and some are actively against it.
The Lean leaders job is to worry about the ones who are actively against the Lean effort. A few of the resisters can be helped to see Lean implementation differently, some can be neutralized, and the remaining you will have to help find other pursuits.
Discuss the goal of maximizing value for the customers and see what happens. If they are for the goal, but uncertain that Lean is the best approach, agree that the proof will be in how well Lean works. Give them time, information, and results.
If they still don’t see the value, discuss how they can still be an asset to the company. If possible, find them the right spot. If this is not possible, make sure they go quickly as they cannot function as a member of the team.
People are critical of Lean Thinking when they don’t understand it or have another approach that they prefer. I believe once they learn what Lean can do, they will support it.
For those who have a more entrenched rejection, often this is a control issue and not something to combat. Don’t judge too soon. People take a while to adapt. Usually when these people finally become convinced they are the biggest. If they are not doing harm, resisters will probably become assets soon enough. Allow the time to grow.