Since I recently completed by Lean Six Sigma Yellow Belt Certification, I wanted to go over the difference between Lean and Six Sigma. Because there are other practitioners of Six Sigma who does not have Lean and vice versa. So in this article, we’ll do a high level take on the two.

In the business world, there has been some debate when it comes to Lean vs Six Sigma. Most people have strong opinions about which method is more effective for cutting costs and eliminating waste. Lean manufacturing is a systematic way of eliminating waste and creating flow in the production process, while Six Sigma is a set of techniques that strive to greatly reduce the rate of defects.

Essentially, Six Sigma and Lean systems have the same goal. They both seek to eliminate waste and create the most efficient system possible, but they take different approaches toward how achieving this goal. In simplest terms, the main difference between Lean and Six Sigma is that they identify the root cause of waste differently. - Villanova University

Every business has areas that need improvement and sometimes it can be hard to know where to start. And as the debate over Lean vs Six Sigma continues in the business world you may not be sure if either method is right for your company.

Although many people compare Lean vs Six Sigma, they can often be more powerful when used together. This article will look more closely at the differences between Lean vs Six Sigma and the benefits of both.

The History of Lean Manufacturing

Lean manufacturing is not new, the ideas behind it were originally introduced by Henry Ford. He liked to keep the production standards incredibly high so that each step flowed naturally into the next, thus resulting in very little waste.

Toyota then accommodated this process and developed the Toyota Production System, which became one of the most efficient systems in the world.

The biggest difference between Lean vs Six Sigma is that they view the causes of waste very differently. The ultimate goal of lean manufacturing is to reduce waste by eliminating bottlenecks and improving the quality of your products.

Lean identifies seven areas of waste that are common in most production systems. Let’s look at each of the “seven deadly wastes” in more detail.

The 7 Deadly Wastes

Overproduction: This occurs when products are being produced that there is no customer demand for.

Waiting: Waiting is the lag time in between each step in production. When employees are left waiting no value is being added.

Transport: This type of waste occurs when materials or products are moved inefficiently.

Motion: Motion refers to poor work standards and employees moving inefficiently between tasks.

Over-processing: Over-processing occurs when you spend too much time producing a product or produce it in a very inefficient way.

Inventory: This happens when your inventory levels are too high and you have too much work in progress at one time.

Defects: Defects are the number of time employees spend identifying and fixing production mistakes.

Implementing Lean will allow employees to move materials less frequently which will improve the quality and require less overall inventory. It also allows quality issues to be dealt with during the manufacturing process, which saves both time and resources because employees aren’t scrambling to fix mistakes later.

All of the improvements listed above will result in a more successful manufacturing process. As the products are being produced and delivered on time, the customers will have a more satisfying experience. And because the products were produced to a higher standard of quality, there will be fewer customer complaints.

The History of Six Sigma

Another main difference in Lean vs Six Sigma is that lean is used primarily in production while Six Sigma can be used to reduce errors in production as well as non-production environments.

Six Sigma looks to reduce waste and it defines a defect as anything that doesn’t meet the customer’s expectations. It focuses more on eliminating any variation in the customer experience. A Six Sigma company will produce no more than 3.4 defects for every million opportunities.

Six Sigma was introduced in the 1980’s by an engineer for Motorola named Bill Smith. Smith believed that by getting rid of variation you can improve the customer experience and increase your overall savings.

Six Sigma has helped Motorola save millions of dollars in revenue. After witnessing Motorola’s success, other companies have adopted Six Sigma and seen dramatic savings as well. General Electric, Toshiba, Bank of America, and Intel have all adopted Six Sigma principles and seen dramatic improvements.

DMAIC

One of the main differences between Lean vs Six Sigma is each method implements process improvement. Six Sigma does this primarily by using DMAIC. DMAIC stands for define, measure, analysis, improvement, and control. Here is a more in-depth look at each step of the process:

Define: In this first step, you will define the problem and how it is affecting the current process.

Measure: During this step, you will measure the current data. By examining the process that is already in place and identifying what isn’t working you can begin finding ways to make improvements.

Analysis: Now that you have measured all of your current data, you can begin analyzing it to get to the root of the problem.

Improvement: This is the step where you will come up with solutions, test your solutions, and make improvements as needed.

Control: Once you have implemented a new process you must continue to make improvements over time. These changes will only last if employees continue to refine and maintain the process.

Lean vs Six Sigma

Although we are comparing Lean vs Six Sigma, the truth is they both work toward the same ultimate goal: eliminating waste and creating efficient processes. They simply take different approaches on how to accomplish this.

Lean focuses on analyzing workflow to reduce cycle time and eliminate waste. Lean strives to maximize value to the customer while using a few resources as possible. Six Sigma strives for near perfect results that will reduce costs and achieve higher levels of customer satisfaction.

To summarize the main difference between Lean vs Six Sigma, lean looks at ways to increase flow while Six Sigma focuses on achieving consistent results.

One similarity between Lean vs Six Sigma is that both have demonstrated that it is possible to dramatically improve the quality of your products and customer experience by improving processes. And as this article points out, when most companies set out to improve inefficient processes they feel like must choose only one method going forward.