Lean vs Six Sigma: What’s the Difference?

Organisations are always striving to improve their business processes, reduce waste, and enhance customer satisfaction. Thus, it is vital for them to understand the Difference Between Lean vs Six Sigma, two popular methodologies significantly recognised by companies in the pursuit to progress.

While these approaches share the common goal of streamlining operations and improving overall performance, they have distinct principles, tools, and applications. While Lean focuses on minimising waste and enhancing process flow, Six Sigma concentrates on reducing defects and process variation. But, there more to understand about their differences.

This blog will help you learn the Difference Between Lean vs Six Sigma, which describes a methodical approach to eliminating waste from organisational systems. 

Table of Contents 

1) What is Lean?

2) What is Six Sigma?

3) Key Difference Between Lean and Six Sigma 

4) Lean vs. Six Sigma: Which methodology is a better option for you?

5) Conclusion 

What is Lean? 

Lean, also referred to as ‘Lean Manufacturing’ or ‘Lean Thinking’, is a management philosophy and methodology that originated in the automotive industry. It was further popularised by Toyota as the Toyota Production System. 

It focuses on maximising customer value while minimising waste, ultimately improving efficiency and reducing costs. Lean principles and techniques have since been adopted by various industries worldwide, revolutionising the ways by which organisations approach Process Improvement.  

Now the core principle of Lean is to identify and eliminate waste, which refers to any activity or process that is not valuable from the customer’s perspective. Organisations can streamline their operations and eliminate waste, thus achieving significant improvements in productivity, quality, and customer satisfaction.  

One of the fundamental concepts in Lean is value. Organisations implementing Lean understand that value is defined by their customers, and all activities must be aligned to deliver that value. They can focus on identifying the value-added activities and eliminate or minimise non-value-added activities in the process.  

Furthermore, another important concept in Lean methodology is the value stream. A value stream is the sequence of steps and processes involved in delivering a product or service to the customer. 

Lean practitioners use value stream mapping, which is a visual representation of the entire value stream, to identify areas of waste, bottlenecks, and inefficiencies. This identification enables them to pinpoint specific areas for improvement and prioritise their efforts.  

Additionally, Lean emphasises the importance of flow, which refers to the smooth and uninterrupted movement of work through a process. Organisations can eliminate barriers and bottlenecks and thus improve cycle times, reduce lead times, and increase overall process efficiency. The ultimate goal is to create a seamless flow of work from start to finish, minimising delays and waiting times.  

Moreover, Lean also promotes the concept of pull, which is a demand-driven system where products or services are produced only when needed. Organisations can strive to avoid overproduction and excess inventory, thus reducing costs, minimising waste, and responding immediately to customer demand. 

The lean methodology identifies seven categories of waste which are common across most production systems. Here is a brief look at the list of the seven categories:

a) Overproduction: Occurs in cases where unwanted products are made

b) Waiting: Refers to the duration of lag between each production stage 

c) Transport: Occurs because of inefficient movement of materials or products

d) Motion: Poor work standards and inefficient movement of employees during tasks

e) Over-processing: Excess time spent producing products in an inefficient fashion

f) Inventory: Inventory levels crossing their capacity leading to work-overload 

g) Defects: Number of times spent by employees in identifying and tackling production errors

What is Six Sigma? 

Six Sigma is a data-driven methodology and management philosophy that focuses on reducing defects and variation in processes. The concept aims to improve quality, efficiency, and customer satisfaction. Developed by Motorola in the 1980s, Six Sigma has gained widespread recognition and adoption across industries as a powerful tool for improving processes and solving problems.  

It is vital for organisations to understand How Does Six Sigma Work, to achieve near-perfection by systematically identifying and eliminating sources of variation and defects. The term “Six Sigma” refers to a statistical measure that represents a level of quality where the probability of a defect occurring is extremely low, with approximately 3.4 defects per million opportunities.   

Six Sigma follows a structured problem-solving approach known as ‘DMAIC’, which stands for Define, Measure, Analyse, Improve, and Control. This methodology provides a systematic framework for tackling Process Improvement projects, including the following:
 

a) Define: Clearly define the problem or opportunity for improvement and establish project goals. This stage involves understanding customer requirements and expectations.

b) Measure: Collecting and analysing data to measure the current performance of the process and identify areas for improvement. This step involves identifying key process metrics and establishing a baseline. 

c) Analyse: Conduct in-depth data analysis to identify the root causes of defects and variation. Statistical tools and techniques are employed to understand the relationship between process inputs and outputs.

d) Improve: Implementing solutions to address the identified root causes and improve process performance. This stage focuses on testing and implementing process changes that lead to significant improvement.

e) Control: Establishing controls and monitoring systems to sustain the improvements over time. Control plans are developed to ensure that the improved process remains stable and continues to deliver the desired results. 

Six Sigma practitioners utilise a range of statistical tools and methodologies to drive Process Improvement. These tools include hypothesis testing, Design of Experiments (DOE), Statistical Process Control (SPC), and process capability analysis, among others. By leveraging data and statistical analysis, organisations can make informed decisions and identify the most effective improvement strategies.  

Furthermore, Six Sigma promotes a culture of data-driven decision-making, where decisions are based on facts and data rather than assumptions or opinions. It emphasises the importance of measuring and analysing performance, setting goals, and continuously monitoring progress towards those goals.

Implement Lean Six Sigma principles by signing up for the DMAIC Training now! 

Key Difference Between Lean and Six Sigma 

The table below highlights the Key Differences Between Lean and Six Sigma:

Lean vs Six Sigma: Which methodology is a better option for you? 

Lean and Six Sigma are two different methodologies, serving different purpose. The Lean methodology can be the perfect fit for a company which looking for a  simple and iterative  framework that can help them drive growth and improvement. On the other hand, the Six Sigma methodology will be better suited if the organisation intends to minimise unpredictability and further improve their efficiency in a complex corporate setting . 

Furthermore, the Lean and Six Sigma methodologies can be combined to bring about a new hybrid method called ‘Lean Six Sigma’. This method can help organisations get the best out of both frameworks. Moreover, organisations can find the implementation of the Lean Six Sigma framework very effective for reducing costs and waste. The framework especially allows the company to improve its operational and quality of the outputs.

More importantly, there is no one-size-fits-all-solution in this scenario as companies can make a choice or charter their framework as a combination of both methodologies, enjoying the rewards of the new hybrid model in the long-term. 

Conclusion

This blog has discussed the Difference Between Lean vs Six Sigma, which are two powerful methodologies that improve processes through their distinct approaches to improvement. 

By employing a methodology suitable for their needs, organisations can achieve comprehensive and sustainable improvements in their operations. As a result, they can drive  a competitive advantage in today’s dynamic business environment. 

Improve your business and drive  customer satisfaction by signing up for our Lean Six Sigma Certification Training now!