Lean vs. Six Sigma: Which Method Is Right for You?

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If you have a manufacturing business, you’ve likely heard of the process improvement methodologies Lean and Six Sigma.
Lean has been around for a long time, starting in manufacturing and spreading to other areas like HR. Comparatively, Six Sigma is a newer approach. They’re often discussed together because they improve processes and boost bottom lines.
But they’re quite different.
Lean focuses on making processes more efficient and faster by cutting waste. Meanwhile, Six Sigma aims to reduce errors and variations.
So, which is better: Lean or Six Sigma?
In this article, let’s explore what makes Lean and Six Sigma unique, how they work, and which might be the best approach for your business needs.
Let’s take a deeper look into Six Sigma’s history and what it entails.
It all began with an engineer named Bill Smith at Motorola in the mid-1980s.
He developed the Six Sigma methodology to improve the quality of production processes by reducing variability and defects.
The term ‘Six Sigma’ comes from statistics, referring to processes operating at no more than 3.4 defects per million opportunities.
In 1986, Motorola formally introduced Six Sigma as a company-wide quality improvement initiative and ended up saving millions of dollars in revenue. Due to this success, Motorola became the first company to win the Malcolm Baldridge National Quality Award in 1988.
Inspired by Motorola’s success, Six Sigma was quickly adopted by two major companies in the 1990s: Allied Signal and General Electric (GE).
Throughout the 2000s, Six Sigma evolved by integrating older quality management ideas with new data-driven techniques.
Today, it has become a global standard for quality management and process improvement. It’s widely used across industries, including manufacturing, healthcare, finance, and information technology.
Recently, Six Sigma merged with lean manufacturing principles to improve process flow, efficiency, and quality. This created the Lean Six Sigma methodology, which has been adopted by many major companies worldwide.
DMAIC is one of the core components or principles of the Six Sigma methodology.
It’s a data-driven quality strategy for improving processes and outlines 5 phases with dedicated objectives and tools:
With a solid grasp of Six Sigma’s origin and principles, let’s now turn our attention to Lean.
Lean project management originated from Toyota’s manufacturing practices in Japan after World War II.Â
Often referred to as the Toyota Production System (TPS), this systemic approach developed by Taichi Ohno aimed to improve efficiency, eliminate waste, and enhance product quality.Â
The term ‘lean’ was coined much later, in the 1980s, after researchers from the West published a book highlighting the effectiveness of TPS.
Lean aims to create more value for customers with fewer resources by optimizing processes and eliminating waste. The key lean principles include:
Lean and Six Sigma are not the same. So, how do they differ from each other? Let’s find out.
There are several similarities between these two methodologies:
Lean and Six Sigma originated in Japan’s automotive manufacturing and were later adopted by Western manufacturers. While Lean has various versions, both methods share a common goal: boosting process performance by eliminating waste, defects, and variations.
Plus, both rely on a data-driven approach, making changes based on data analysis and measurable metrics rather than assumptions.
Customer satisfaction is equally central to both Lean and Six Sigma, with a strong emphasis on creating value for customers. And the process for this value creation is often led by cross-functional teams.
Regardless of your chosen methodology, both techniques are huge promoters of continuous improvement. They encourage you to constantly review and optimize workflows to increase their efficiency and effectiveness.
But there are also several differences between these two methodologies:
1. Waste: Lean and Six Sigma define waste differently. Lean sees waste as any process or activity that doesn’t add value to the customer. So, lean practitioners focus on optimizing processes to increase customer value.
In contrast, Six Sigma identifies waste as a result of variation within a process. People who use this method work to eliminate defects and waste by reducing this variability.
2. Methods and approaches: Lean is a mindset based on principles that guide smarter decision-making. It uses methods like Kaizen events, value stream mapping, 5S, and TPM to continuously increase value and eliminate waste. This approach works best when it becomes part of the organization’s culture and everyone participates.
On the other hand, Six Sigma is a structured program that uses DMAIC and DMADV (Define, Measure, Analyze, Design, Verify) to reduce variability and risk.
It comes with a ‘belt’ certification system, where people at different levels have specific roles:
3. Tools and functional areas: Lean’s origins are in software development, so it’s still used in forms like Kanban, agile methodologies, and Scrum. Many sectors prefer its visual tools to add customer value.
Because of its arsenal of statistical methods, Six Sigma is great for complex environments that require reduced variability and risk. It’s applied in areas such as manufacturing and engineering but can become an issue for small companies due to resource limitations.
Lean takes the help of visual methods to improve business process management.
For example, it uses value stream mapping to depict the sequence of activities, information flow, and handoffs within a business process. This way, you can easily identify waste, bottlenecks, and areas that require attention.
In addition to eliminating waste with 5S and Kanban methods, Lean also tries to establish an uninterrupted flow of work using techniques like single-piece workflow. It standardizes work procedures through documentation, training, and visual controls.
Lean continuously improves the process by reducing setup times. It uses Single-Minute Exchange of Die (SMED), a powerful tool that dramatically reduces the time it takes to switch between production runs of different products on the same equipment. It also analyzes root causes (with methods like the 5 Whys) and involves everyone in Kaizen events.
Six Sigma, however, relies on statistical principles. It heavily emphasizes data-driven decision-making, employing statistical tools throughout its DMAIC approach (Define, Measure, Analyze, Improve, Control).Â
Common statistical assumptions include:
The method uses various statistical tools at different stages to pinpoint root causes and maintain the improvement of processes. Some of these are:
Plus, Six Sigma checks data accuracy with measurement system analysis (MSA) in the Measure phase, ensuring it’s reliable for decision-making.
4. Leadership: If teamwork is your priority, Lean is the way to go. Its flexible structure allows teams from all levels (from individual contributors to executives) to collaborate, solve problems, and think broadly.
Six Sigma has a structured, hierarchical leadership model, which is great for highly organized companies. Its certified roles range from local problem-solving to leading projects and training teams.
Here’s an overview of the differences between Lean and Six Sigma:
| Aspect | Lean | Six Sigma |
| Goal | Process improvement | Process improvement |
| Definition of waste | Process or activity that adds no value to the customer | Results from variation within a process |
| Approach | Mindset based on principles | Structured program with a belt certification system |
| Methods | Kaizen events, value stream mapping, 5S, TPM | DMAIC and DMADV |
| Metrics tracked | Cycle times, inventory levels, flow metrics | Defects per million opportunities (DPMO) |
| Functional areas | Software development companies of any size | Suitable for big, complex organizations |
| Tools | Visual tools, single-piece workflow, SMED, 5 Whys | SPC, DOE, statistical analysis tools |
| Leadership | Flexible, great for collaboration | Hierarchical, works best for highly organized companies |
Lean and Six Sigma have their fair share of benefits and limitations.
Whether it’s Lean or Six Sigma, you can implement either of them in your organization by following the steps below:
First things first, you’ll have to get top management to support and commit to Lean or Six Sigma as a key part of the organization’s goals and strategy. Ensure the company leaders are on board to effectively drive whichever methodology you choose.
Find a strong reason to start Lean or Six Sigma, like resolving customer complaints, quality problems, or process inefficiencies. Without a clear reason, motivating people to use these methods effectively might be harder.
Once you have sorted out your reasons, build a program structure that handles planning, training, project selection, and oversight.
Time is of the essence when it comes to business. And if you don’t want to wait too long for the outcome, choose high-profile projects that can show quick results. Starting with projects that provide visible and immediate improvements can build momentum and support for further efforts.
Now that you know what process you’ll move ahead with, it’s time to get your teams up to speed. Train your employees on Lean or Six Sigma principles, tools, and techniques to ensure everyone has the necessary knowledge and skills to use them.
The next step is to identify the goals and objectives that correspond to the areas of problem that you need to resolve. Set specific, measurable, achievable, relevant, and time-bound (SMART) goals to guide the process as smoothly as possible. Map current value streams or define project charters for the targeted problems.
For proper leadership, bring in experts who understand Lean or Six Sigma like the back of their hands. They can help motivate your teams and show them the value of these methods.
Involve influential people, like senior and middle managers, in the process along with them. Their support is crucial for the successful adoption of the Lean Methodology or Six Sigma.
After that, implement your plan. Use the right set of tools and lead Kaizen events or DMAIC projects to drive improvements in your project execution process. Also, ensure systems are in place for collecting, analyzing, and monitoring process/quality data.

ClickUp is an all-in-one, AI-powered project management software that simplifies daily business processes with comprehensive tools and features.
It also has a huge library of templates to help you get started on various project management processes and techniques, including Lean or Six Sigma.
If you’re struggling with Lean and want to keep track of your business plan steps without wasting resources, use the ​​ClickUp Lean Business Plan Template. It prioritizes agility and validation over lengthy, traditional plans.
This template helps you quickly create a lean and high-level plan without starting from scratch. It provides a clear structure to guide you through defining your business model, target market, goals, finances, and more. However, it also offers flexibility to adapt to your specific needs.
It gives a complete overview of your business strategy and an easy-to-follow outline for your business plan, along with step-by-step guidance for each section.
Benefits of using this template:
However, if you want to streamline specific business areas, such as production or customer service, try ClickUp’s Process FMEA Lean Six Sigma Template.
It combines Lean Six Sigma (a combined version of the two methods) and FMEA (Failure Mode and Effects Analysis) into one place to help you systematically identify failure modes, their occurrence and detection probabilities, and actions to mitigate effects and causes.
It’s perfect for recognizing process risks, clarifying improvement areas, and creating an action plan with team alignment.
This comprehensive template simplifies the process by allowing you to:

You can also use ClickUp’s Whiteboard to visualize your Lean and Six Sigma implementation processes, identify bottlenecks, and collaborate on implementation steps and strategies with your team. It’s a versatile tool for mapping out workflows and simplifying operations.
The Whiteboard offers a fully customizable canvas for brainstorming, strategizing, and mapping business processes.
You can use it to:
A set of well-structured, smooth-flowing processes is the cornerstone of a successful business, and both Lean and Six Sigma are designed to achieve this.
However, they can seem quite complicated to even experienced project managers. A way to simplify them and achieve the outcomes you’re aiming for? ClickUp!
With project management features, customizable templates, and 1000+ integrations, ClickUp can handle all your business processes irrespective of your chosen process improvement method.
Not only will your production be error-free, but it will also be backed and handled by AI-powered tools and features to ensure you’re on top of everything from a single platform.
Sign up for ClickUp today and let it help you manage your process improvement methods with ease!
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