Giving the fact that many customers may be interested to implement their projects thru Lean and/or Six Sigma, A lot of people get confused between them.

In this Article I will introduce you to the methodologies of Lean , Six Sigma and Lean Six Sigma. People with no experience in this area can get an idea what it is all about. So let's begin:

Section I: Lean Methodology

What is Lean ?

Lean is a set of problem solving tools to reduce or eliminate activities that don't add value to the process. It emphasizes removing wasteful steps in a process and taking only value added steps. The Lean method ensures high quality and customer satisfaction. It is a never ending process of waste removal.

What is "Value" ?

Depending on the type of business process, the customer defines value. The activities can be classified into three types. They are:

Non- Value added activity: These activities do not add any value to the process. They form the wasteful steps.

Value added activity: These activities add value to the process and are essential. They improve processes for productivity and quality.

Enabling value added activity: These activities do not add value to a customer. They are necessary for continuity of a business process.

Removing Waste

Using the Lean methodology, you can remove these eight types of waste. "DOWNTIME" is the acronym for the eight wastes.

The Five Principles of Lean

These Lean principles can be applied to any process to reduce the wastes. They are:

1. Value Stream Mapping: The customer defines the value of a product or service. The activities are classified into three parts: Non Value added, Value added and Enabling value added. The value stream mapping shows the workflow process steps for a product or service.

The value mapping process helps to identify and eliminate non value adding activities. This helps reduce the delays in a process and improve quality of service.

2. System Beat Time: The beat time is the rate at which a product must be ready to meet the customer demand. This ensures smooth workflow of the process without any disruptions.

3. Root Cause Analysis: It is necessary to find out the root cause of waste in a process. Using the 5 Why's tool and a cause and effect diagram is an effective way of root cause analysis. Here is a sample image:

4. Balancing and Workflow Management: Systems designed on beat time principles allow easy workflows. The production system must be able to handle customer demands at any time.

This means use of resources/materials on a need basis. It is known as Load balancing. This means replacing material used for building a product. It also helps to remove excess inventory.

5. Improving the system: There must be consistent efforts to improve the existing business process as per changing customer needs. This ensures removal of waste and quality service to customers.

Now let us read about management approach of Six Sigma.

Section II: Six Sigma

What is Six Sigma ?

Six Sigma is a data driven problem solving methodology. The focus is on process variations and emphasis is given to customer satisfaction. Continuous process improvement with low defects is the goal of this method.

Goal of Six Sigma:

The Six Sigma method aims for a process to be 99.99996 % defect free. In other words, a process results in 3.4 defects per million opportunities or less.

Problem solving in Six Sigma is done using the DMAIC/DMADV framework. There are five stages in this DMAIC framework. They are Define, Measure, Analyze, Improve, Control. Also five stages through DMADV framework, they are Define, Measure, Analyze, Design, Verify.

Section III: Lean Six Sigma

So far we have read about the methodologies of Lean and Six Sigma. The next question on everyone's mind would be "What is Lean Six Sigma"? Let's find out......

Lean Six Sigma combines the strategies of Lean and Six Sigma. The principles of Lean Six Sigma help to improve the efficiency and quality of the process.

In this management approach, the lean methodology is used first to remove the waste in a process. After this is complete, the Six Sigma tools are used to improve process variations. The combination of these two methods helps to develop streamlined processes with high quality.

The Lean Six Sigma management approach finds wide application across industries. It leads to rapid changes in an organization's performance. Lean Six Sigma has become popular in various companies in the world. They can be product or service oriented companies. The LSS method has improved processes making them efficient. This is possible because of total employee involvement and commitment to customer satisfaction.

Practitioners of Lean Six Sigma are given "Belts" signifying level of experience.


I hope you understood the differences between these three management approaches. They have their benefits when applied to different business processes. They improve the quality of existing processes and make you a better manager.



Source: Ahmed El-Askalany, CSTE, CSQA, PMP, CQIA, ITIL