What is Lean Six Sigma?

What are the principles of Lean Six Sigma?

As its name suggests, Lean Six Sigma is the combination of two continuous improvement methods: the Six Sigma method and Lean Management.

Lean Management was developed by the Toyota company in the 1950s in Japan. It is a work organisation system that aims to improve company performance by reducing waste.

The Six Sigma method was developed in the 1980s by Motorola and then by General Electric. It is a process optimisation method that aims to eliminate production defects by using performance indicators.

These two methodologies are complementary and can become a formidable performance tool when used together. Indeed, both methods aim to improve performance: while Lean Management seeks to make the process efficient, Six Sigma aims to eliminate process variability. By combining the two approaches, a company is more likely to achieve satisfactory performance.

Thus, to implement Lean Six Sigma, it is necessary to apply Lean Management and Six Sigma in parallel. To do this and achieve this performance, waste must be eliminated continuously and permanently, within the framework of Lean Management, and Six Sigma tools must be implemented within the framework of specific projects.

What are the 8 types of waste?

Let’s start by reminding in this article the 8 types of waste, which are often at the origin of the process limits. In the following paragraph we will see how to apply the Six Sigma approach in addition.

1. Overproduction

Overproduction is the main waste in companies. Indeed, it generally generates significant costs, linked to the accumulation of stocks and the cumbersome nature of the flows.

2. Excessive stocks

This second waste, which is often a consequence of the first, is very costly for the company.

3. Defects

Defects on the production line should be avoided as much as possible, as they make it necessary to carry out time-consuming and costly corrective operations. The company’s reputation can also be directly affected by production defects, if they reach the customers.

4. The non-value added stage

Non-value-added steps are actually quite numerous on production lines. They slow down the process, cost the company a lot of money and are a direct obstacle to the optimisation of flows.

5. Waiting times

Waiting times can be a consequence of breakdowns, malfunctions or other problems on the production line, and strongly penalise the company’s productivity.

6. Unnecessary movements

This sixth form of waste costs a lot of energy and time and often requires a review of the overall organisation of the process.

7. Unnecessary displacement

This waste is complementary to the previous one. It also costs resources and could be avoided by representing the physical flows of operators in order to reorganise the different production stations.

8. Under-utilisation of skills

Know-how, business knowledge and collective intelligence are often under-utilised in companies. This leads to a loss of efficiency, unnecessary recruitment and demotivation of employees. It is therefore very important to optimise the use of skills.

What is DMAIC and DMADV?

DMAIC is one of the key methods for implementing the Six Sigma approach. It is a 5 step quality improvement process:

• Define the problem,
• Measure the data that affects the outcome of the process,
• Analyse this data using statistical tools to assess the feasibility of the solution,
• Improve the identified problem with solutions,
• Check the sustainability of the solutions implemented.

DMADV is also a methodology of the Six Sigma approach. It stands for Definition Measurement Analysis Design Verification. It is also a methodology in 5 phases:

• Definition of the problem and objectives,
• Measurement of data and parameters,
• Analysis of options and design alternatives,
• Design of the chosen alternative using the results of the previous step,
• Verification of the chosen design.

What is the difference between the DMAIC and DMADV methodologies?

Although these two methodologies may seem similar, they are in fact used in different contexts.

The DMAIC methodology is used when the product has already been marketed and the aim is to improve the production process so that it is closer to customer expectations.

Conversely, the DMADV methodology is used when the product has not yet been built and is still being designed.

What are the benefits of Lean Six Sigma?

Lean Six Sigma is so widely used in companies because of its many benefits.

In addition to reducing costs and improving product quality, it increases employee involvement and motivation.

The main benefits of Lean Six Sigma are :

• Increased profitability: eliminating waste and improving quality through the combined methods of Lean Management and Six Sigma increases the profitability of the company by reducing costs.
• Simplified and standardised processes: Lean Six Sigma makes processes more efficient, which tends to simplify them.
• Involvement of employees at every stage of the process: the human capital is enhanced by this method, which increases the productivity and motivation of employees.
• Satisfied customers: the most expected consequence of process improvement is increased customer satisfaction, which has a positive impact on customer loyalty.

Thus, by combining the best of both approaches, Lean Six Sigma enables a drastic improvement of processes in companies.

Written by Emma Guignard