3-Phase Lean Academy
Module 6: Lean Approaches, A3 Thinking & Introducing 3-Phase Lean
3-Phase Lean · 45-60 minutes

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Module 6 3-Phase Lean 45-60 minutes

Lean Approaches, A3 Thinking & Introducing 3-Phase Lean

3-Phase Lean Academy: a self-paced module based on the book by Damian D. Reese

What you'll be able to do

By the end of this module, you will be able to:

Section 1

Many Roads to Improvement

There are many approaches to facilitating a Lean improvement effort, ranging from the very strict and rigid to the flexible and approachable. All of them share the same DNA: Value, Waste elimination, Flow, and Continuous Improvement. They differ in ceremony, statistics, and dogma.

This module tours the major approaches, then introduces the one this Academy is named for: 3-Phase Lean, which distills the essentials of its predecessors into a method anyone can use, in any industry or personal situation, without the headache of rigorous methodology.

Knowing the landscape matters even if you only ever use 3-Phase Lean. You will meet Six Sigma belts, TPS veterans, and Lean Startup founders in your improvement work, and understanding their language earns their trust.

Section 2

Lean Six Sigma and DMAIC

Lean Six Sigma (LSS) is the most widely known and complex methodology. It combines Lean principles with Six Sigma, a data-driven approach that uses statistical analysis to identify and eliminate defects. It shines in industries with high complexity and variability: healthcare, finance, telecommunications, government, and manufacturing.

Six Sigma aims for quality that is effectively free of defects: 3.4 defects per million opportunities. The name refers to six standard deviations from the mean in the process capability calculation. Improvement follows a structured five-step method called DMAIC: Define, Measure, Analyze, Improve, Control.

Six Sigma fun facts

Those two examples show both the power of six sigma quality and the scale required to make the statistics meaningful. For most everyday improvement work, that machinery is more than the job needs, which is exactly why 3-Phase Lean exists.

Section 3

The Toyota Production System and "Stop the Line"

TPS is the original Lean approach, developed by Toyota in the 1950s on the principles of respect for people and Continuous Improvement, involving employees at all levels.

The famous "stop the line" policy

In every Toyota plant, every worker is empowered, and expected, to pull the emergency stop cord at their station when they spot a defect anywhere on the automobile, even one that happened at a previous station. The entire line stops, and designated responders from each area swarm to the defect to address it immediately.

Even the tiniest defect is treated as extremely valuable, and the employee who finds it is honored. Defects become treasures to be found, not embarrassments to be hidden or ignored.

The rumble strip story

In the 1980s, an American consulting team toured Japanese automotive plants to see "stop the line" in action. Back home, they visited an American plant to compare. The first thing they noticed: the line rarely stopped for defects. The second: a long rumble strip of closely spaced speed bumps that every finished vehicle drove over on its way off the line.

When they asked what it was for, the Americans explained: it was to see if anything falls off, so the vehicle could be sent to the warranty department for repair instead of being cleared for shipping.

One system stops production to fix the cause of a defect the moment it appears. The other shakes the product to find out what the defects were. "Stop the Line" has since been adopted in most US manufacturing plants, and "Stop the Line for Safety" has spread to healthcare and other industries where human safety is at risk.

Section 4

LEI, Lean Startup, and Kaizen

And then there is the sixth approach on the book's list: 3-Phase Lean, which incorporates many of the principles of all the others, with the tools and processes simplified and the dogma removed. Before we meet it, one more piece of shared heritage: the A3.

Section 5

A3 Thinking

Every Lean approach follows its own methodology, but they all traditionally document improvement work on a large-format visual page called an A3.

An A3 is a structured format for documenting and analyzing a process. The name simply refers to the paper size, commonly known as 11x17 (precisely 29.7 x 42 cm, or 11.7 x 16.5 in). Whatever the measurement, the A3 is the standard documentation tool for improvement projects: one page, visible at a glance, carrying the whole story of the improvement.

Different methods fill the page differently. Lean Six Sigma A3s use the rigid DMAIC format. Most Lean practitioners use a 5-Box, 7-Box, or 9-Box A3. The 9-Box has become the standard in recent years, partly because it aligns with DMAIC well enough to compare Lean and LSS outcomes side by side.

Diagram

The 9-Box A3 Format

A3 Header Info (title, team, dates) Reason for Action Current State Target State 3-PHASE LEAN: PHASE 1 territory Gap Analysis Solution Approach Rapid Experiments PHASE 2 territory Implementation Plan Sustainment Plan Project Review PHASE 3 territory

The 9-Box A3: nine boxes in a 3x3 grid documenting the improvement from reason to review. The color bands preview how 3-Phase Lean simplifies it.

Section 6

Introducing: 3-Phase Lean

The 9-Box method is highly effective. It is also intimidating. So the book simplifies the elements of a 9-Box A3 into a method called 3-Phase Lean. The reason is approachability:

"I want every person, in every industry and every personal situation, to be able to improve processes and solve problems without the headache of rigorous methodology and dogma."

3-Phase Lean is the heart of the Lean for Everyone mission. Same proven Lean bones, one-third the ceremony:

Phase 1 Cut the Clutter Phase 2 Fix the Flow Phase 3 Sustain the Success
Section 7

The Three Phases

Phase 1: Cut the Clutter

The focus is identifying and eliminating Waste in the current process. It starts with a thorough analysis of the Current State: areas of inefficiency, delays, bottlenecks, and unnecessary steps. The key tool is Process Mapping, which visualizes the steps being performed and the Flow of materials and information. This phase also puts techniques to work: Kanban to improve Flow and reduce Waste, 5S to improve workflow, and Visual Management to bring hidden Waste to the surface. (Module 7 covers this phase step by step.)

Phase 2: Fix the Flow

This phase centers on identifying and addressing the bottlenecks and issues hindering performance and blocking your goals. It analyzes data and applies problem-solving tools like Root Cause Analysis and the 5 Whys to find the Root Cause of each problem, then optimizes the Flow of materials and information while improving the Value the process delivers. (Module 8.)

Phase 3: Sustain the Success

The final phase maintains and continuously improves the gains. Standard Work and a Sustainment Plan make the improvements long-lasting; measuring results and auditing processes ensure improvements hold and issues are caught quickly. This phase is what separates real transformation from a temporary cleanup. (Module 9.)

Whether you are improving a manufacturing plant, streamlining office processes, or making your own life run more smoothly, 3-Phase Lean is an effective and accessible path. The next three modules walk each phase in detail, with the specific tools for each step.

Practice

Try It Yourself

Reflect

How could your organization involve employees at all levels in improvement, the way TPS does? How could you adapt a "stop the line" policy where you work, and what would have to be true for people to feel safe pulling the cord?

Activity

Write down some problems you would like to solve or processes you would like to improve. For each, ask: which Lean approach fits best? Which would be the biggest win? Which is the quickest win? Which is the most urgent? Keep this list; it becomes your raw material for the next three modules.

Recap

Key Takeaways

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Knowledge Check

7 questions. Answer at your own pace, then check the explanation for each.

Question 1 of 7
What does DMAIC stand for?
Correct answer: B. DMAIC (Define, Measure, Analyze, Improve, Control) is the structured methodology used by Six Sigma.
Question 2 of 7
Six Sigma quality corresponds to approximately how many defects?
Correct answer: C. Six Sigma aims for quality that is effectively free of defects: 3.4 defects per million opportunities, or 99.99966% perfection.
Question 3 of 7
In Toyota's "stop the line" policy, what happens when a worker spots a defect?
Correct answer: C. Every worker is empowered and expected to stop the line. Defects are treated as treasures to find, not problems to hide, unlike the American plant with its rumble strip.
Question 4 of 7
In Lean documentation, what does "A3" refer to?
Correct answer: B. A3 is the paper size (29.7 x 42 cm / 11.7 x 16.5 in). The A3 document is the standard one-page tool for documenting and analyzing improvement work.
Question 5 of 7
3-Phase Lean was created by simplifying the elements of which format?
Correct answer: B. 3-Phase Lean simplifies the 9-Box A3 into three approachable phases, keeping the proven structure while removing the dogma.
Question 6 of 7
What are the three phases of 3-Phase Lean, in order?
Correct answer: C. Phase 1: Cut the Clutter. Phase 2: Fix the Flow. Phase 3: Sustain the Success. Memorize these; they are the backbone of the rest of the course.
Question 7 of 7
Which phase of 3-Phase Lean focuses on analyzing the Current State and eliminating Waste, with Process Mapping as its key tool?
Correct answer: A. Phase 1 analyzes the Current State, identifies inefficiency and bottlenecks, and uses Process Mapping plus Kanban, 5S, and Visual Management to cut the clutter.
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Module 6 complete

Nice work. Review any section again using the menu (top right), or move on.

Continue to Module 7: Phase 1: Cut the Clutter →

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