Lean and Six Sigma - Different?

By Larry Cote, Managing Director

A recurring theme in the hundreds of companies/organizations we have worked with is that they are very often unsure of how to differentiate between Lean, Six Sigma and Lean Six Sigma. Its imperative to understand the differences to integrate them effectively.

Let’s establish a simple basic difference between Lean and Six Sigma and then determine an effective way to utilize both concepts.

WHAT IS LEAN?

Lean is an approach – a way of thinking - about how you should run your business. While it is not a tool, Lean does require many tools both for analysis and implementation of change to execute on the vision and direction created by Lean thinking. Lean focuses most of the attention on the customer and what the customer feels is “value”. Value is defined by an activity that transforms the product or service requested by your customer. Essentially, it is any activity the customer would be willing to pay for.

To determine what is value to the customer, you would apply a tool called Value Stream Mapping (VSM). This analytical tool is not Process Mapping (we will explain the difference in an upcoming article). VSM is a graphical representation of the process from end-to-end, highlighting all the activities that are both Value and Non-Value. From this Current State you are able to create the ideal Future State (FS) - the ideal FS which is the FS with most of the waste/non-value identified becomes the vision and direction of the organization. The next step is to create an initial 3-month FS (typical length) which moves the company in the direction of the ideal FS.

The initial 3-month FS is a tactical strategy which is displayed on a detailed Implementation Plan outlining the improvement activities (Kaizens), the tools required for specific improvements, the people required to complete the improvement tasks and the expected results at the end of the Implementation Plan. The goal being to remove, or at least minimize, the non-value effectively and have a positive impact/result on the end-to-end process.

As mentioned, the FS Implementation Plan will also identify any tools you will require to take you to the next level of efficiency and quality. One of these tools may very well be Six Sigma.

SO WHERE DOES SIX SIGMA FIT IN?

Six Sigma is a very effective tool for reducing or eliminating variation throughout the value stream. It is a data-driven methodology and set of techniques for process improvement. Its primary goal is to identify and eliminate defects or inefficiencies in business processes, aiming for near-perfection. Without reducing variation, creating an effective flow is challenging.

For example, imagine a cabinet manufacturing company facing issues with inconsistent finish quality on their cabinets. By applying the DMAIC (Define, Measure, Analyze, Improve, Control) process, they would first define the problem and measure the current level of defects in the finishing process. Analysis might reveal that the inconsistencies are primarily due to variations in the spray application process and differences in drying times. The team could improve the process by standardizing the spray techniques and introducing controlled drying environments. Finally, they would control the process by setting up regular maintenance checks on the spray equipment and training employees on the new standardized procedures. As a result, the finish quality could become consistent, leading to a smoother production flow and higher customer satisfaction.

To successfully apply Six Sigma, there must be a well-defined Current State analysis and Future State Implementation Plan. Without this Plan, you won’t have a clear path for improvement. Considering that Lean principles often identify many activities in your current end-to-end process as non-value-added, attempting to apply Six Sigma effectively without conducting a Current State analysis may be a waste of time. When you assign a Six Sigma expert to “fix” a problem and reduce the variation, you want to make sure you are asking them to work on an area that supports the transformation to the new FS process.

COMBINING THE TWO CONCEPTS

There is a simple solution to effectively using both Lean and Six Sigma. First, use the thinking and analytical approach of Lean and establish a Future State Implementation Plan. Once you have this plan, it will determine the tools that are required and where they are needed. This includes where the tool Six Sigma is required, and the Six Sigma experts should focus their attention. The Six Sigma specialist become an integral part of the strategy/direction of the company and team, while recognizing their essential role in the Lean transformation. These specialists are no longer working in isolation and “wasting” time on problems that would be eliminated or changed in the Future State.

IN SUMMARY

Lean is a way of thinking and has an effective structured methodology for developing a sustainable transformation of a business or any organization. Lean identifies the critical tools needed to take your company to the next level of excellence, competitiveness and profitability while improving the culture within the company. Lean thinking and methodology impact both culture/sustainability and operations/processes. Lean leadership then has a constant mandate and that is to maximize the ’value’ to the client. As they, and their staff, wander about their facility (in the office and on the floor) they will constantly ask themselves, ‘would the client be willing to pay for that activity in the process if they knew you were doing it?’. This is true continuous improvement thinking.

Six Sigma is one of the possible tools that will be required as the organization moves from Current State to Future State. It focuses on analyzing variation and determining the root cause of the variation. Most companies we deal with are not close to Six Sigma level of quality (perfection) and will find they need to start with other less intense quality tools and approaches. Six Sigma is critical in industries where safety is key – aerospace, healthcare, food processing etc.

Knowing how to adapt and apply Lean and Six Sigma properly to get the most out of these concepts, you are able to accomplish true success - reducing costs, while improving quality and service to your customer by maximizing the utilization of your resources (people, space and equipment/technology.)