Lean Six Sigma blends two leading process improvement methodologies: Lean and Six Sigma. In a nutshell,
- Six Sigma focuses on eliminating defects in a process.
- Lean focuses on creating value for a customer by eliminating waste.
Dr. Robert Elliott III, a highly recognized practitioner, instructor and Lean Six Sigma Master Black Belt, says:
“Lean and Six Sigma have proven themselves to both be effective over the past 30 years. There is no reason to choose a camp. The approaches clearly complement one another, and there is really no reason not to be engaged in Lean Six Sigma to drive performance today.”
Let’s take a more in-depth look at each methodology, then see how they are used together.
The History of Lean
Lean, with its focus on eliminating waste, has its roots in Henry Ford’s mass automobile production plants from the early 20th century, according to the Lean Enterprise Institute. Ford developed methods for eliminating any wasted activity or variance from the process. His plants excelled at making the Model T, but stumbled somewhat when consumers’ tastes changed and other cars needed to be manufactured.
Taiichi Ohno of Toyota famously took Ford’s concepts and expanded upon them. He and others at the Japanese carmaker created the Toyota Production System. While also focused on eliminating waste and defects, the system also allowed for more variance in manufacturing. Toyota is now the leading Lean exemplar and No. 1 vehicle manufacturer in the world.
Many organizations turn to Lean because it allows for quick implementation and continuous improvement through fast trial and error. Using Lean helps to accelerate the overall benefits of Six Sigma. While it involves a set of strategies and tools, successful implementation of Lean also involves adopting a Lean culture.
The foundation for Lean culture is a focus on continuous improvement. This supports not only making changes to improve an operation, but also sustaining those changes and making further adjustments as needed.
The focus for Lean is on defining what is valuable to customers and aligning an operation to meet those needs. All process steps are evaluated through the lens of providing value to customers. Steps that do not add value are eliminated. When implementing Lean, activities are divided into three main areas.
- Non-Value Added: These activities add no value to customers and should be eliminated.
- Value-Added: These are key activities that add value to the customer while also improving processes to add better quality and efficiency.
- Enabled Value Added: These activities may not directly add value to the customer, but are essential to the business operation.
The Eight Wastes
Using Lean tools and strategies, organizations identify areas of waste. There are eight main categories of waste:
- Defects: Mistakes and errors in a process.
- Over-Production: Producing more product than needed or before it is needed.
- Waiting: Time wasted while waiting for the next step in a process.
- Non-Utilized Talent: Not fully using people’s knowledge, skills and talent
- Transportation: Moving products and materials unnecessarily
- Inventory: Having too many products or materials that are not being used in the process
- Motion: Movements made by workers that are not necessary to the process
- Extra-Processing: More work or a higher standard of work than is needed by the customer
What is Lean Six Sigma?
Six Sigma started with Motorola in the 1980s. The data-driven methodology was used to find defects in the company’s manufacturing processes. The goal of Six Sigma is to have no more than 3.4 defects per one million opportunities.
Lean and Six Sigma together form Lean Six Sigma by focusing on process, people and purpose for operational excellence.
Lean Six Sigma Tools
Lean Six Sigma comes with a variety of tools that help an organization identify and eliminate waste, while also providing a better product or service. The emphasis is on adding value to a customer.
Some of the most popular tools include the following:
- Value Stream Mapping: Every operation in a process is identified and then placed into a value stream map that includes the three “values” categories listed above. This quickly allows organizations to find parts of a process than add no value.
- System Beat Time: This simply involves setting a firm deadline for when a product should be ready to meet the expectations of customers. Adhering to a timeframe ensures a smooth workflow.
- Root Cause Analysis: This involves finding the underlying reason for any of the eight wastes listed above.
- The Five Whys: A popular Lean tool used in root cause analysis, it involves stating a problem and then asking (at least) five questions to get to the root of an issue. Here’s a simplified example of the Five Whys in use for a common issue.
The problem: We are not responding in a timely fashion to customer questions via social media.
- Why? There is a backlog of responses waiting to be sent to the customers.
- Why? It takes two weeks to get answers to customer queries approved.
- Why? All answers must be approved by a top executive and that doesn’t happen regularly.
- Why? There is no set schedule for doing this.
- Why? The social media team has not set up a standardized approval schedule system.
A simple meeting to set up a routine schedule for approving responses to customers can solve the issue. It may also involve the executive agreeing to designate someone on the social media team to approve the responses at a faster rate.
Lean Six Sigma Certification
Getting certified in Lean Six Sigma can help employees become successful in working on projects involving both Lean and Six Sigma. The levels of certification are as follows.
White Belt: The most basic level, learning terminology and basic concepts.
Yellow Belt: Building on basics to work with putting the methodology into practice.
Green Belt: A higher level of understanding of the methodology, allowing Green Belts to often assist on projects.
Black Belts: Leaders on Six Sigma and Lean projects who have mastered tools and strategies and overseen putting them into action.
Master Black Belts: Black Belts with substantial experience in overseeing Six Sigma and Lean projects. Master Black Belts take on key leadership roles in implementing process improvement.
Lean offers a complementary system to Six Sigma. It also offers employees the chance to learn new, valuable skills. Ultimately, the biggest beneficiary are customers who receive faster and improved services and products.