Most AI tools hand you an answer. This one checks your thinking before you take it to your team. Bring a draft A3 or a change you are about to present, and it asks one question at a time, in the Toyota sensei tradition.
01What this is
Most people describe AI as something that gives them an answer. The people who get the most out of this one use it the other way around. They think the problem through first, or write the first draft, and then bring it here to find out what they missed.
Lean Coach is built by Mark Graban, author of Shingo Award-winning books including Lean Hospitals (3rd edition) and host of the Lean Blog Interviews Podcast. It runs on the Claude API from Anthropic, draws on specific source material rather than the open internet, and is tuned away from the instinct to answer first and ask later.
It is not neutral about everything. Respect for People and psychological safety are not positions to debate; they are the ground the coaching stands on.
Coach
What is the current state?
Mark
About 41 percent of people who sign up for my free trial never ask a single question. They give an email, land in the tool, and leave. I have been assuming it is a UX problem with the empty input box.
Coach
What have you actually watched them do -- have you sat with a session recording, or is 41 percent coming from an analytics dashboard?
Mark
Analytics dashboard only.
Coach
That is the gap worth naming. You have a number, but no observation of what actually happens in those sessions. Before testing any UX fix, what would it take for you to watch five of them?
An unedited exchange, in Coach Me mode, about a problem on this site.
02Two modes
Most of the time, coaching is the point. But there are moments when you need a definition, a reminder, or a quick reference. Lean Coach has two explicit modes. You choose which one is running.
Default
Socratic. One question at a time.
The default posture. The coach asks what you have seen, what you think is happening, and what you would try next. It will not hand over a conclusion a question could teach you. Slower on purpose.
"What have you observed at the gemba in the last week that made you think this is a standard-work problem?"
On request
Direct answers, still grounded in the source.
When you already know what you need and the question is factual, switch to Tell Me. The coach answers directly, cites the method, and stops. It still will not invent Lean concepts it does not know.
"Standard work has three elements: takt time, work sequence, and standard work-in-process. Here is how they fit together..."
You can switch at any time by saying "coach me" or "tell me." The mode persists until you change it.
03What this is not
It is not a replacement for a real coach or sensei. It is what a good coach would ask you between sessions, available at 9pm on a Tuesday when your sensei is not.
04Choose a version
Same method, different source material and vocabulary.
One request before you start: do not ask it a test question. Bring something you are actually stuck on. It is built for real work and does not perform well as a party trick.
Not sure what counts? Something like:
For healthcare
Grounded in Lean Hospitals (3rd ed.). Vocabulary and examples from clinical and hospital operations.
It will not accept patient information. If you paste any, it redirects you.
leanhospitalsbook.com/start Start free trialFor everyone else
Grounded in core Lean principles and thirty-plus years of practice across manufacturing, services, and knowledge work.
Free for 48 hours, full access, no credit card. Email required to start. A handful of emails follow over the first week, then nothing. After 48 hours, access ends unless you subscribe.
05About Mark
Author of Shingo Award-winning books including Lean Hospitals (3rd edition) and host of the Lean Blog Interviews Podcast. Thirty-plus years of Lean and continuous improvement practice with manufacturers, hospitals, and knowledge-work teams. More at markgraban.com.