Lean or Six Sigma? Which is Which?

Do you know your Lean from your Six Sigma? How about your PDCA vs. DMAIC? If not, then today’s article will provide you with everything you need to know! We look at the fundamental differences between Lean principles and Six Sigma methodology. We also look at the different focuses, tools, and techniques of each. So join us as we ask, Lean or Six Sigma? Which is which?

What Does Lean Focus On?

Lean focuses on reducing the eight types of waste (Muda).  Defects, overproduction, waiting, non-utilized talent, waste from transportation, inventory waste, waste from motion, unnecessary processing. Additionally, Lean principles aim to reduce waste by identifying and eliminating it. Lean also improves production by maximizing flow and identifying non-value-adding steps you should remove. Anything that does not add value for the customer is a potential threat to production. As such, Lean uses a holistic approach that aims to build a culture of continuous improvement and in-depth analysis.

Lean Principles, Tools, and Techniques

• PDCA. Standing for Plan, Do, Check, Act, PDCA is a rapid cycle-based strategy used to drive process improvement.

• 5S is a 5-step method for creating and maintaining an intuitive and efficient workplace. The 5 Ss stand for Sort, Set In Order, Shine, Standardize, Sustain.

• 8 Types of Waste. Lean aims to eliminate the eight waste types: defects, overproduction, waiting, non-utilized talent, waste from transportation, inventory waste, waste from motion, and unnecessary

• Value Stream Maps. VSMs are a visual method for displaying the key process steps in production.

• Flow is the unhindered movement of a process.

• Pull describes how customer demand is used to dictate process flow, i.e. what the customer wants, or might want, determines what a company produces.

What does Six Sigma Focus On?

Six Sigma and Lean share many similarities. As such, they complement each other very well. However, Six Sigma focuses primarily on reducing variation, just one of the seven types of waste Lean tackles. Six Sigma is used to complete improvement projects, aimed at solving process issues. It is also highly data-oriented, involving validation of hypotheses using statistics. Six Sigma knowledge is classified using a belt-based hierarchy styled on martial arts (Yellow, Green, Black, and Master Black Belt). The higher the belt, the more adept you are at using Six Sigma. Furthermore, one of Six Sigma’s primary tools is a 5-step method with which to complete improvement projects.

Six Sigma Ideas, Tools, and Techniques

• DMAIC. This 5-step method uses the following steps, Define, Measure, Analyze, Improve, and Control to improve production processes. Furthermore, DMAIC also allows you to identify the problem and develop creative solutions through deep analysis.

• Project Charter. Six Sigma uses a single-page document to outline the process issue, project goal, scope, and a timeline. Moreover, the charter forms an essential framework for the trajectory of an improvement project.

• Pareto Chart. Pareto Charts display information about potential causes of process issues in a cascading bar chart format. Additionally, you should also organize problems from largest to smallest.

• Hypothesis Testing. Hypothesis Testing is a way of providing statistical precision to root causes of process problems, so you can make the best decisions.

• Design of Experiments. Methods of controlled testing, with which to assess how efficient processes are. DoE also allows you to select the best conditions, materials, and methods for each.

• Statistical Process Control. SPC enables you to monitor your processes, ensuring they consistently satisfy customer demand.