Although it is an internationally recognized methodology widely used by large companies in the market, the term Lean Six Sigma still raises questions among some professionals.
Many people do not see Lean and Six Sigma as distinct philosophies that complement each other in a productive process. Therefore, if you are part of those who still confuse these two terms you need to better understand the difference between them.
First of all: What is Six Sigma?
Six Sigma is a management philosophy aimed at solving problems and reducing process variability, significantly reducing costs for the company, thus increasing its profitability.
Different from what many people think, Six Sigma is not only a tool that seeks the adaptation of companies to quality standards, the focus of this methodology is directly linked to customer satisfaction.
That is the reason why Six Sigma works on process optimization to improve quality in the organizational environment, resulting in more standardized and stable products and services, developed within the limits of acceptance imposed both by the process itself and by the customers.
What is the difference between Six Sigma and Lean?
Lean Manufacturing is an operational philosophy that involves the analysis of the 8 main wastes in the production line, line optimization and continuous improvement with the application of quality tools.
In other words, this methodology aims at eliminating processes and activities that do not add value to the client.
With reduced waste and increased process efficiency, Lean achieves a significant reduction in the time between customer order and delivery, resulting in a reduction in the costs involved.
Although the two methodologies have the purpose of directly impacting the profitability of an organization, they act differently within a production system.
While Six Sigma works to reduce variability and process defects to make it more effective, Lean aims to make the process more efficient by reducing waste and increasing production speed.
Why Lean Six Sigma?
Lean Six Sigma is the combination of the two methodologies.
The term emerged to unite the Six Sigma methodology with the tools and concept of Lean Manufacturing in order to improve the company's results by reducing the variability in its processes and by eliminating waste and non-value adding activities.
How can I apply each of the methodologies within my company process?
Let's assume you work at a brewery and the production line you're responsible for bottles Pilsen beers in 600 ml bottles.
Imagine that the internal standard of this brewery considers as conforming, that is, within the limits of specification, every bottle with a variation smaller than 10% in volume.
Consider that your production line bottles 1000 units per minute and that on average 4% is out of the required standard, so leave the process with a volume change greater than 10%.
Now at the end of the year, its main customer has requested a greater quantity of products and to meet this demand, its line should bottle 980 beers per minute, within the specified limit.
How would you apply Lean Six Sigma to improve this process?
In order to deliver the quantity requested by your customer you need to increase the speed of your production, right? If the line bottled a bottle every 0.060 seconds, now you need to reduce that time to 0.058 seconds.
One way to reduce this time would be to apply the Lean methodology using its tools to make the process more efficient. Understood?
And where does Six Sigma fit in? You need to pack 980 bottles per minute into the standard, so you need to keep the process variability under control and you need to ensure that your process does not produce outside of the company's specification limits, considering the 4% limit, the which is possible through the application of the methodology.
While Six Sigma has a focus on quality, reducing process variation, Lean focuses on increasing productivity by reducing waste and improving workflow.
Improving quality also leads to better productivity, but the reverse is not always true. Did you see the difference now?