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Six Sigma vs Lean Six Sigma: What's the Difference? - Purdue

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Six Sigma vs Lean Six Sigma: What’s the Difference?

Home<br>Blog<br>Six Sigma<br>Six Sigma vs Lean Six Sigma: What’s the Difference?

7 June, 2021

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Even the most proven business tools and approaches must adapt as time goes on, morphing to suit the state of the market and today’s companies. Six Sigma is no exception, with multiple branches, disciplines, and schools of thought having grown from the original concept over the years to fit new needs.

In one case, two different schools of thought have merged into a single, cohesive methodology that can address multiple goals. This is Lean Six Sigma, a combination of management methods that builds on the principles of Six Sigma with a focus on efficiency. Both approaches aim to achieve the same thing: more effective processes that yield a bigger bottom line. The difference is seen in the way they go about reaching that goal.

Six Sigma

Six Sigma was developed with a very specific goal: reduce variation and defect rates in production processes through statistical analysis. To do this, Six Sigma uses one of two, 5-step approaches – either the DMAIC or the DMADV method.

Both methods have their distinct uses. DMAIC stands for Define, Measure, Analyze, Improve, and Control. This process involves identifying the problem you’re trying to solve, taking stock of your current processes, identifying and implementing a solution, and maintaining that solution in the future. This is perfectly suited for supply chain performance issues or when only adjustments to the process are needed, not an entirely new function.

That’s where DMADV (Define, Measure, Analyze, Design, Verify) comes in. The first phases of the project are the same, but the Design phase allows for the creation of an entirely new tool to solve the problem. The Verify phase then focuses on ensuring that the new solution does, in fact, continue to solve the problem.

Six Sigma, then, is all about monitoring the supply chain for defects, identifying issues, and solving them as effectively as possible.

The Lean Method

The Lean method, on the other hand, is entirely focused on eliminating waste, providing maximum value to customers with the lowest possible amount of investment. The term Lean was first used to describe the Toyota Business System in the 1980’s, a business philosophy that helped the company run at maximum efficiency. It involves every tier of an organization, helping guide new processes and drive the allocation of resources. The primary difference between Lean and Six Sigma is that Lean is less focused entirely on manufacturing, but often shapes every facet of a business.

Lean Six Sigma combines these two approaches, which creates a powerful toolkit for addressing waste reduction. As companies seek to understand where they may have wasteful practices in place, the DMAIC method provides an excellent road map for identifying and solving the problems they face. This synergy between methodologies functions primarily to help eliminate the 8 kinds of waste, removing anything from a process – whether its material, time, or effort – that doesn’t add value. The forms of waste are:

Defects – Products that don’t meet quality standards

Overproduction – Exceeding demand or producing more than was ordered

Waiting – Process bottle-necks and downtime

Non-Utilized Talent – Ineffectively using or misallocating human resources

Transportation – Inefficient shipping methods

Inventory – Holding on to a surplus of product or raw material

Motion – Unnecessary moving of product, material, or people

Extra Processing – Doing more work than is needed

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