Lean Problem Solving: How to Fix the Root Cause and Keep the Problem From Coming Back
Every operation I have walked into has a problem everyone knows by name. It was fixed last month, and the month before that.
It was never solved. It was only patched, and patches wear off.
Direct answer: Lean problem solving is a structured way to fix a problem at its root cause and then prevent it from returning: define the problem with data, contain it, find the root cause with tools such as the 5 Whys and a fishbone diagram, put a countermeasure in place, standardize the new method, and verify that the problem stays gone. Most recurring problems come back because teams stop after containment. At Gurley Leadership Solutions, I teach this method in person to teams across Durham Region and the Greater Toronto Area as a Lean Certified Six Sigma Black Belt.
Why Do the Same Problems Keep Coming Back?
The same problems keep coming back because most teams treat the symptom and stop, which contains the problem but leaves its cause in place. The Canadian Centre for Occupational Health and Safety puts the emphasis on finding the root cause so that the event can be prevented from happening again, and the same rule applies to scrap, late orders and billing errors.
| Response | What it does | Example | Stops it returning? |
|---|---|---|---|
| Containment | Stops the damage today | Sort and rework the bad parts | No |
| Correction | Fixes this occurrence | Replace the worn tool | Rarely |
| Root cause countermeasure | Removes the cause | Tool life added to the maintenance schedule | Yes |
| Prevention | Stops similar causes elsewhere | Same schedule rolled out to every line | Yes, more widely |
All four have a place in lean problem solving. The mistake is stopping at the first two.
What Is Lean Problem Solving?
Lean problem solving is the discipline of fixing problems where the work happens, with data, by the people who do the work, until the cause is removed. ASQ describes the root cause as the core issue that sets in motion the entire cause-and-effect reaction, and says it should be permanently eliminated through process improvement.
It is one part of a wider system. For the full picture of value streams, the 7 forms of waste and how an organization rolls this out, see my guide to Lean Six Sigma implementation.
How Do You Solve a Problem So It Stays Solved?
You solve a problem so it stays solved by moving through the six steps of root cause problem solving in order and not skipping the last two, which is where most teams stop.
- Define it with data. What happened, where, how often and how much it costs. "Quality is bad" is not a problem statement.
- Contain it. Protect the customer today while you investigate.
- Find the root cause. Use the 5 Whys and a fishbone diagram with the people who do the work, and check each cause against the data.
- Put a countermeasure in place. Change the process, not just the part, and test it small first.
- Standardize it. Write the new method down, train the wider team, and make it the way the work is done.
- Verify it. Track the measure for weeks, not days, and confirm the problem has not returned.
Together, the six steps of lean problem solving follow the Plan, Do, Check and Act (PDCA) cycle. ASQ describes the 5 Whys, originally developed by Sakichi Toyoda, as a questioning process designed to drill down into the details of a problem.
What Does a 5 Whys Example Look Like?
A 5 Whys example follows one problem down through its causes until you reach one the team can change and that would stop the problem if removed.
| Why? | Answer |
|---|---|
| Why did the order ship late? | The line stopped for two hours |
| Why did the line stop? | A machine overheated |
| Why did it overheat? | The coolant filter was clogged |
| Why was the filter clogged? | Nobody changed it on schedule |
| Why was it not changed? | Filter changes are not on the maintenance checklist |
An illustrative example. The countermeasure is adding filter changes to the checklist, not telling the operator to watch the temperature.
Notice the last answer points to a process, not a person. If your 5 Whys ends with someone's name, ask one more why.
How Do You Prevent Problems Before They Start?
You prevent problems by building the countermeasure into how the work is done, so the next problem never needs a 5 Whys. This is where lean problem solving pays back the time it takes.
| Prevention habit | What it prevents | Where to start |
|---|---|---|
| Standard work | Variation between people and shifts | Your most repeated task |
| Visual controls | Problems hiding until it is too late | A board at the line |
| Error-proofing | Mistakes reaching the customer | Your top defect |
| Preventive maintenance | Breakdowns | The machine that stops most |
| Leading indicators | Surprises at month end | One weekly measure per goal |
From my Lean and Six Sigma work in senior operations roles, including Honeywell, Johnson Controls and Armstrong Fluid Technology.
Why Does Leadership Decide Whether Lean Problem Solving Works?
Leadership decides it because people only surface problems when the leader asks "why did this happen?" instead of "who did this?". When the first question is blame, problems go underground and come back bigger.
John Robinson, a former Johnson Controls colleague and retired VP of Continuous Improvement, wrote: "Over the years I found Malcolm to be a true driver for change with a great deal of enthusiasm and charisma which positively impacted other people at Johnson Controls. His understanding of business processes provided significant insights both in identifying best practices but also in implementing the changes."
The honest caveat: lean problem solving alone will not fix a culture that punishes people for raising problems. If your team keeps fixing the same issue, a 15-minute call is usually enough to see whether the gap is the method or the leadership around it.
Who Teaches Lean Problem Solving in Durham Region?
Online guides explain the tools well; in-person lean problem solving training on your own problems is what makes the method stick.
Quality Gurus notes that the 5 Whys often considers only one root cause, which might oversimplify complex problems, and FranklinCovey points out that lag measures are history: by the time you see them, the performance that drove them has already passed. Both are strong resources for large organizations. For Durham Region and Greater Toronto Area teams that want customized, local and measurable results, my approach is the better fit: I work with your team in person, on your real problems, until the countermeasures hold. You can read about my background and why employers choose Gurley Leadership Solutions.
What Is the Bottom Line on Problem Solving and Prevention?
Lean problem solving comes down to this: contain the problem today, remove the root cause this month, and build the fix into standard work so it never returns.
- Choose a 5 Whys template if one simple problem needs a quick root cause.
- Choose a self-paced online course if one person needs to learn the tools.
- Choose in-person Lean Six Sigma training with Gurley Leadership Solutions if the same problems keep returning and your team needs to solve them for good.
The tools come from Lean and Six Sigma. The leadership habits that make a team use them every week come from a proven program from Leadership Management International, customized to your organization; see the Leadership Management International programs. I deliver both in person in Ajax, Whitby, Oshawa, Pickering, Clarington and across Durham Region and the Greater Toronto Area.
Which Problem Keeps Coming Back in Your Operation?
A 15-minute call with Malcolm Gurley is enough to find where to start and what to contain first.
416.669.7644 · Monday to Friday, 8:00 AM to 6:00 PM · Ask about government funding options when you book your call.
Book a 15-Minute CallWhat Do Teams Ask About Lean Problem Solving?
What is lean problem solving?
Lean problem solving is a structured method for fixing problems at their root cause and preventing them from returning. Teams define the problem with data, contain it, find the root cause with tools such as the 5 Whys and fishbone diagram, put a countermeasure in place, standardize it and verify the result over time.
What are the steps of root cause problem solving?
Root cause problem solving follows six steps: define the problem with data, contain it to protect the customer, find the root cause, put a countermeasure in place, standardize the new method, and verify that the problem has not returned. Together, the six steps of lean problem solving follow the Plan, Do, Check and Act (PDCA) cycle.
What is the 5 Whys method?
The 5 Whys is a questioning technique, originally developed by Sakichi Toyoda, that asks why a problem happened, then why that cause happened, about five times, until it reaches a cause the team can remove. A good 5 Whys ends at a process, not a person. For complex problems it is often paired with a fishbone diagram.
What is the difference between problem solving and problem prevention?
Problem solving removes the cause of a problem that has already happened. Problem prevention builds habits such as standard work, visual controls, error-proofing, preventive maintenance and leading indicators into daily work, so that similar problems never start. Strong teams do both, and every solved problem should feed a prevention habit.
Who offers lean problem solving training in Durham Region?
Gurley Leadership Solutions in Ajax, Ontario, led by Malcolm Gurley, delivers Lean Six Sigma and lean problem solving training in person for teams across Durham Region and the Greater Toronto Area. Malcolm is LMI Canada licensed, Lean Certified and a Six Sigma Black Belt with 35+ years of senior executive experience, including Honeywell and Johnson Controls. Call 416.669.7644.
Malcolm Gurley brings 35+ years of senior executive experience with Honeywell, Johnson Controls and Armstrong Fluid Technology. He is LMI Canada licensed, Lean Certified and a Six Sigma Black Belt, a member of the Ajax Pickering Board of Trade, and delivers Leadership Management International programs and Lean Six Sigma training in person across Durham Region and the Greater Toronto Area from Ajax, Ontario. Facts on this page were checked against ASQ and CCOHS on October 14, 2026. Frequently asked questions
Sources and References
- Canadian Centre for Occupational Health and Safety (CCOHS), Incident Investigation, revised June 23, 2025 (ccohs.ca)
- ASQ, What is Root Cause Analysis (RCA)? (asq.org)
- ASQ, Five Whys and Five Hows (asq.org)
- Gurley Leadership Solutions published testimonials (gurleyleadershipsolutions.com)
