Lean Six Sigma

The Principles Of Lean Six Sigma

Ranga .V Srinivas, Guest Blogger

Lean Six Sigma

What is Lean Six Sigma? What is the difference between Lean Manufacturing and Six Sigma? Which one to implement first Lean or Six Sigma? These are the questions many manufacturing and service industries are asking.

The answer to these questions depends upon whom you are asking. The answer you get has some common threads, like eliminating waste or NVA (non value added) activities in your process, eliminate variance in your process etc.

For me the answer is simple Lean Six Sigma is eliminating 3Ms in your process (Manufacturing or Service area), i.e. eliminate MUDA (waste), MURA (Variance) and MURI (un-evenness) in your process. Use Lean tools to eliminate MUDA first, then use Six Sigma tools to eliminate MURA and again use advanced Lean tools to eliminate MURI.

The most common Lean Six Sigma methodology used by many Fortune 100 companies including CHEVRON, KRAFT FOODS, VERIZON, AT&T, EXXON, Lockheed Martin, Raytheon etc is DMAIC ((pronounced “duh-may-ik”). DEFINE, MEASURE, ANALYZE, IMPLEMENT and CONTROL. It is a 16-step process.Each step has several questions, deliverables for each question, Date to complete, and recommended tools to use.

Before start using this methodology one should be trained as Green Belt and/or Black Belts. To ensure the senior managements understand the Lean Six Sigma process, all senior managers (decision making authority in an organization) must be trained as White Belts (1-2 days of training)However, before beginning the process, you’ve got to set yourself up for success. How’s that done? By making sure that you select the right projects.


Before beginning any process improvement project, it’s vital that you choose projects that are good candidates for improvement. A good project for improvement:

  • Has an obvious problem within the process
  • Has the potential to result in increased revenue, reduced cost or improved efficiency
  • Has collectable data

DMAIC (Lean Six Sigma) is also a system of management that results in a steady pipeline of projects. Lean Six Sigma provides guidelines to help you select the right projects at the right time. Once projects are selected, improvement team(s) led by a trained Green Belt or Black Belt can use DMAIC to further refine the projects and deliver quantifiable, sustainable results.



The Define Phase is the first phase of the Lean Six Sigma improvement process. In this phase, the Champion, Sponsor and GB/BB of the project create a Project Charter, create a high-level view of the process (SIPOC), and begin to understand the needs of the customers of the process (VOC). This is a critical phase of Lean Six Sigma in which the teams define the outline of their efforts for themselves and the leadership (executives) of organization. In this phase we use Lean Tools like VSM, Process Map, Six Sigma tools VOC (voice of Customer), VOB (Voice of Business)


How does the process currently perform? Measurement (VOP-Voice of the Process) is critical throughout the life of the project and as the team focuses on data collection initially they have two focuses: determining the start point or baseline of the process and looking for clues to understand the root cause of the process. Since data collection takes time and effort it’s good to consider both at the start of the project (during the DEFINE phase). In this Phase we use Six Sigma tools such as MSA (Measurement System Analysis), Gage R&R.


What does your data tell you? This phase is often intertwined with the Measure Phase. As data is collected, the team may consist of different people who will collect different sets of data or additional data. As the team reviews the data collected during the Measure Phase, they may decide to adjust the data collection plan to include additional information. This continues as the team analyzes both the data and the process in an effort to narrow down and verify the root causes of waste and defects. In this Phase we use Six Sigma tools such as Gage R&R, PARETO charts, BOX PLOT, Control Charts, CPk etc.


How will you fix the problem?

At this phase some Companies use GE WORKOUT methodology, which is nothing but a KAIZEN event!

Once the project teams are satisfied with their data and determined that additional analysis will not add to their understanding of the problem, it’s time to move on to solution development. The team is most likely collecting improvement ideas throughout the project, but a structured improvement effort can lead to innovative and elegant solutions. We use Lean tools such as 5S, SMED, TPM, Cellular Manufacturing.


How do you sustain the newly achieved improvement? This phase is the beginning of process management. The team has been building a form of infrastructure throughout the life of the project, and during the Control Phase they begin to document exactly how they want to pass that structure on to the employees who work within the process. We use Lean tools such as Checklists, PDCA checklist, any sustainment check lists, Six Sigma tools such as Control charts.


Many companies send/train their employees in Lean Six Sigma Green Belt or Black Belt courses, but when they are out on field they need a good mentor to mentor them throughout the process. This is where majority of the companies fail. Companies often hesitate to use experienced consultants to mentor their GB/BB to complete the projects resulting in incomplete projects or failing to achieve expected results.

New Jersey manufacturers are enjoying a resurgence of American manufacturing, and now is the time to drive more programs that lead to efficiencies. Contact NJMEP to learn more about how Six Sigma can help your company.

 Image by UW Stout.

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