Lean Six Sigma Methodology: Why the Marriage of Speed and Precision Drives Process Excellence

Lean and Six Sigma are powerful on their own. But together, as the LSS methodology, they create a balanced approach to process improvement. This blog post examines how combining Lean’s speed with Six Sigma’s precision enables organizations to reduce waste, enhance quality, and achieve lasting results across various industries.

In brief:

• Lean eliminates waste and improves flow speed, while Six Sigma reduces defects and enhances quality precision. Together, they address efficiency and accuracy as the LSS methodology.
• Despite misconceptions, LSS works across all industries, not just manufacturing.
• You can deliver quick wins through Lean’s rapid improvements while building long-term capabilities through Six Sigma’s systematic problem-solving.

Lean Six Sigma (LSS) combines the speed of Lean methodology with the precision of Six Sigma to create a powerful process improvement approach that reduces waste, enhances quality, and delivers measurable business results across industries.

Organizations that implement LSS methodology see rapid efficiency gains from Lean’s focus on waste elimination while achieving long-term quality improvements through Six Sigma’s data-driven defect reduction.

Combining these methodologies addresses both flow optimization and quality control from a customer perspective, enabling companies to tackle obvious inefficiencies quickly while solving complex systemic issues methodically.

Here’s a breakdown of each methodology and how they’ve formed a beautiful union that continues to benefit business leaders.

What Is Lean?

Lean manufacturing is the successor of the Toyota Production System (TPS), which Toyota leaders developed in Japan in the mid-20th century. Lean management then arose from Lean manufacturing principles after they became popular in the 1990s.

Today, the Lean methodology benefits all sectors, not just the manufacturing industry. It’s evolved and grown into a mature methodology focused on creating flow and eliminating waste to maximize value.

What Is Six Sigma?

Six Sigma is a set of tools and techniques for process improvement that was developed at Motorola in the 1980s and further popularized by General Electric (GE) in the 90s. Six Sigma has since grown and become a popular strategy for organizations across sectors, including manufacturing, engineering, finance, supply chain, and healthcare.

Six Sigma aims to reduce defects and variations in processes to achieve near-perfect results every time. The goal is to have 3.4 defects or less for every million opportunities.

The formula used to simplify Six Sigma is: Statistical Solutions and Designs = Optimization and Stable Operations

The Six Sigma Framework

The Six Sigma methodology uses a framework called DMAIC. The acronym breaks down like this:

• D – Define problems, goals and requirements
• M – Measure by collecting data to establish a baseline
• A – Analyze the problem to identify the root causes and the relationships between process inputs and outputs
• I – Improve your processes by developing, testing and implementing solutions
• C – Control the success of your process by monitoring the outputs of the revamped process and identifying ways of improving it, as well as making sure it doesn’t revert to its previous state

These phases of the DMAIC process occur in sequence, and while they’re all important, your most critical action steps take place during the “Improvement” step.

How to Maximize the Success of the Improvement Phase

In many cases, the Improvement phase involves the most work and decision-making, making it one of the more delicate elements of the framework. How can you ensure that the Improvement phases deliver on their promise?

First, you must consider the frontline employees who should be involved in the solution design. Additionally, you should pilot solutions before scaling them up.

Here are some tools that winning organizations can use:

Lean and Six Sigma offer different approaches to process improvement. Let’s take a closer look at how these two methodologies, while not necessarily opposites, sit on different sides of the solution spectrum.

What’s the Difference Between Lean and Six Sigma?

Lean and Six Sigma are different methodologies because they involve unique:

• Goals. Lean seeks to reduce waste and improve efficiency, while Six Sigma aims to eliminate defects and improve quality.
• Problems. Lean sets its sights on eliminating delays and inefficiencies, whereas Six Sigma targets defects and errors.
• Philosophies. Lean’s philosophy focuses on creating an efficient sense of flow, while Six Sigma’s philosophy highlights a data-centered, rigorous methodology.

Given their differences, it seems unlikely that Lean and Six Sigma could combine and form a fruitful relationship. Yet that’s exactly what they’ve done. Here’s a more detailed analysis of how and why they complement each other.

How Lean and Six Sigma Complement Each Other

Lean and Six Sigma have grown into a formidable pair. They even have their own moniker: Lean Six Sigma, or LSS. Let’s break down why they fit together so well.

Combining their methodologies allows you to address both flow and quality from a customer perspective. LSS combines rapid improvement with long-term capability building.

Here’s how they work together and some of the tools they use:

• Primary Focus. Lean’s primary focus is eliminating waste and improving flow, while Six Sigma is about reducing variation and improving quality. Lean streamlines a process, while Six Sigma stabilizes and optimizes it.
• Problems. Lean deals with obvious inefficiencies, delays, and non-value-adding activities. Six Sigma focuses on complex issues with hidden root causes. Therefore, while Lean addresses the speed and flow of processes, Six Sigma improves their accuracy.
• Mindsets. Lean’s mindset centers on continuous improvement and employee empowerment. Six Sigma promotes data-driven decision-making and statistical rigor. So, LSS balances people-centric change with analytical precision.
• Speed of Results. Lean offers practitioners fast, incremental improvements. Six Sigma provides more structured, long-term improvements. When used together, Lean can deliver quick fixes while Six Sigma tackles larger systemic issues.
• Desired Outcomes. Lean aims to deliver greater efficiency, shorter lead times, and less waste. Six Sigma’s goals are complementary, focusing on higher quality, fewer defects, and more predictable outcomes. Therefore, at a high level, both aim to enhance customer satisfaction and business performance.

Common Misconceptions About Lean Six Sigma

Despite the methodologies’ popularity, not everyone approves of the LSS relationship. This is often due to some misconceptions about what it involves and how it’s used.

Here are some of the perceptions surrounding LSS, why they’re inaccurate, and how to address them:

Challenges of Implementing Lean Six Sigma

Implementing LSS isn’t without its challenges, and it’s good to know what to expect so you can plan accordingly. Here are some signs of trouble to watch for and how to overcome them:

• Intangible Processes. Processes in the office or in service industries are less tangible than those in manufacturing. Overcome this by mapping processes using swimlane diagrams and Gemba walks, which involve observing work as it happens.
• Limited Data. Service-based processes may not have a lot of data to measure process performance. Overcome this by establishing key performance indicators (KPIs) early on. You can also use estimation or sampling as you begin your analytical processes and then refine your data over time.
• Cultural Resistance. Some employees may perceive the LSS methodology as bureaucratic or intimidating. Overcome this by emphasizing how LSS benefits employees’ daily work, and invite employees to present pain points that LSS can address.
• Complicated Workflows Across Multiple Departments. Processes can vary between tasks and departments, leading to confusion about what to focus on and who to hold accountable. Overcome this by focusing on standardizing only the processes that are a good fit for standardization. Assign process owners early on and set up cross-functional teams for your LSS implementation.

How to Train and Prepare Your Teams for Lean Six Sigma

Preparing your teams to benefit from LSS starts with assessing where your organization is and then designing training accordingly. Specifically, you should:

1. Evaluate Your Current Business Processes

This includes the effectiveness of each process and the amount of data required to assess them. Then, choose low-risk, obvious processes as early candidates.

2. Deliver Role-Based Training

Your training should meet the needs of specific job roles. It must also focus on real-world problems that your teams currently face or may need to address shortly. Also, use a combination of different learning formats, including classroom sessions, online modules, and on-the-job application.

3. Begin With Small Pilot Projects

Your initial projects should be manageable and have clear outcomes, making it easier to demonstrate LSS’s success and apply lessons learned to subsequent projects.

4. Embed Coaching and Membership

Pair people at different levels of LSS proficiency, such as Green and Black belts. Also, encourage community sharing of successful practices.

5. Continue Ongoing Development and Training

Your solution must also implement an ongoing approach to development, which may include refresher trainings and more advanced LSS tools. Be sure to recognize and reward participation to support an LSS-positive culture and boost morale.

Putting LSS to Work for Your Organization

As you use Lean and Six Sigma together, you’ll see why their relationship works. Their differences are complementary. The key is to let each one thrive, focusing on its strengths without expecting it to handle the other’s workload.

Apply Lean principles to enhance efficiency while leveraging Six Sigma-based tools to improve quality. By systematically applying the LSS framework, you can eliminate confusion about what to do and when while keeping everyone on the same page.

Our Process Improvement experts have helped many organizations implement LSS. Connect with us today to discover how we can help you enhance your processes. Let’s talk