TL;DR: Lean and Six Sigma tools help organizations eliminate waste, reduce variation, and improve performance. This guide covers eight essential tools — including 5S, DMAIC, A3, Kanban, and Value Stream Mapping — and explains how they support measurable continuous improvement

Lean and Six Sigma offer dozens of tools — but most organizations only use a handful effectively. Here are 8 essential Lean and Six Sigma tools that drive measurable improvement when applied correctly.

Six Sigma is a business management methodology that leverages a scientific approach to quality measurement with the aim of reducing variation and defects. The method was pioneered by Motorola and Allied Signal and then made famous by GE, which boasted $10 billion in savings during the first years of implementation.

Lean is another methodology, philosophy, toolset, and management system that also uses a scientific problem-solving approach. "Lean" is a generic term applied to the Toyota Production System (TPS). The two pillars of TPS are usually described as "just in time flow" and "quality at the source."

Lean and Six Sigma are often used together by organizations across multiple industries, combining methods and mindsets from both approaches.

Core Lean and Six Sigma Tools That Drive Measurable Results

Many frameworks exist for implementing the methodologies. Many of those tools can be useful to organizations, whether or not they fully embrace the Lean or Six Sigma approaches. Here are a few that our customers have found most valuable.

5S

5S is a workplace organization paradigm intended to improve safety, reduce waste, and streamline the flow of value to the customer. The approach is named after the five principles of Sort, Straighten, Shine, Standardize, and Sustain. (Not coincidentally, each of these terms is translated from a Japanese word that also starts with S when written in phonetic script.)

The 5 Whys

While we’re talking about Lean tools that involve the number five, we should mention the 5 Whys. Keep in mind that one of the essential tenets of Lean is that problems should be addressed at the root cause rather than covered up or worked around. The underlying cause of an issue can often be found by asking the simple question, “Why?” five times. The answer to each question is documented, and the process is repeated until the source of the issue is identified and resolved.

A3 Reports

A3 reports (named after the metric paper size initially used by Toyota) are one-page reports that document everything that is necessary for decision making and reporting for a particular process. They are used to condense information from many sources into one easily digestible and actionable document. They typically include background, the current process flow, analysis, goals, recommendations, and an implementation plan.

Control Charts

Control charts are used to visualize a process's outputs over time. Control charts are a method that predate the terms Lean and Six Sigma and are sometimes associated with either method. They generally have upper and lower control limits that are each three deviations from the mean. Control charts help managers recognize common cause variation, which indicates the process has not changed, and special cause variation, which indicates a problem or a shift in the process or system.

DMAIC

DMAIC stands for Define, Measure, Analyze, Improve, and Control. It is perhaps the most important Six Sigma tool of all. It is an improvement cycle that is used to stabilize, improve, and optimize business processes. Many refer to DMAIC as the Six Sigma roadmap for problem-solving. Once the cycle is completed, and new Standard Work is documented, it can be repeated to achieve additional improvement.

Kanban

Kanban means “shopkeeper’s sign” (or "signpost") in Japanese. It is a visualization methodology that enables just-in-time manufacturing and streamlined workflows in other industries. The idea is to use visual cues to deliver the correct inputs a process needs when it needs them. This means that stock levels of raw materials, components, work in progress and finished goods can be kept to a minimum. Today, many organizations use digital Kanban boards to visualize the movement of work in progress through a process.

Standard Work

It's often said that one of the primary goals of Six Sigma is the elimination of variation, but Lean focuses on that goal, as well. To achieve consistent, predictable results, it is imperative that each process is performed the same way every time, regardless of who is completing the associated tasks. This is achieved through the development, documentation, and enforcement of Standard Work. The Standard represents the current best practice for performing each part of the process. The Standard Work is not set in stone, however. It represents the baseline upon which improvement is measured.

Value Stream Mapping

Value stream mapping is a Lean tool that ensures every part of a process delivers value to the customer. Value is defined as something that the customer is willing to pay for. During the value stream mapping exercise, the current process is documented. Every step, task, or resource expenditure that does not directly produce value is targeted for elimination or improvement.

Turning Lean and Six Sigma Tools Into Measurable Results

Lean and Six Sigma tools are powerful — but they are not self-executing.

Many organizations adopt 5S, DMAIC, Kanban, or Value Stream Mapping with strong intentions. Yet tools alone do not produce sustained improvement. Results come when those tools are embedded into a management system that encourages daily problem solving, accountability, and learning.

The difference between isolated projects and lasting transformation is discipline.

Leaders must:

• Align tool usage with strategic priorities
• Ensure problems are addressed at the root cause
• Standardize successful improvements
• Engage employees as active contributors

When Lean and Six Sigma tools are treated as checklists, improvement stalls. When they are integrated into daily management, they become engines of performance.

The goal is not to use more tools.

The goal is to use the right tools consistently — in a system that reinforces continuous improvement.

Organizations that make that shift do not just complete projects.

They build capability.

And capability compounds.