Six questions to a Lean/Six Sigma Master Black Belt from an Engineering Undergrad Student

Mentoring is an important part of continuous improvement.  Through the process of mentoring both parties have an opportunity to learn.  The following are six questions that I fielded from an engineering undergrad.

What is the best way to learn Design of Experiments (DOE)?

To develop a deep understanding of Design of Experiments (DOE) you will need to understand what DOE is, why you would use DOE, how to implement DOE, and only then start practicing DOE. This will require significant investment of time and energy, but the results can be very rewarding. Being successful with DOE will require an excellent understanding to statistics as a baseline to work from. Greenbelts and Black Belts should work directly with a Master Black Belt to develop proficiency.

So what is DOE? DOE is a method to systematically investigate process and/or product variables that are impacting quality. It can help you identify factors that truly impact your product or process while minimizing the number of times you would need to run a test.

Why would you use DOE? DOE is a great approach to use when trying to understand inputs that are driving a result while simultaneously reducing the costs of experimentation. Imagine you are trying to find the optimal temperature and cooking time for the perfect pizza. One approach would be to test random temperatures and cooking times through trial and error. You might guess correctly the first time or you might need to test 1,000’s of times. DOE is used to arrive at the optimal settings with far fewer tests.

How to implement DOE? DOE is typically carried out in four phases: Planning, Screening (aka process characterization), Optimization, and Verification.

In the planning phase you will define the problem, define the goals (knowledge to be gained), and develop an experimentation plan. You will also need to ensure that both the process and the measurement are in control. You will need a firm grasp of Statistical Process Control (SPC) in general with a deep understanding of Gage R&R.

In the screening phase you will need to reduce the number of factors or variables to be tested to the most likely few. Some tools you should be comfortable with to accomplish screening are Two-level full and fractional factorial designs, Plackett-Burman designs, General full factorial designs, and/or Principal Component Analysis (PCA).

After screening you will now need to Optimize. This is what is typically considered DOE to most. You will find the best or optimal values of inputs that produce the desired output. The best method for this will depend on the goal you defined above. Are you trying to reduce variability or maximize yield? The path you follow you determine if you need Factorial Designs, Response Surface Designs, Mixture Designs, or Taguchi Designs.

The last step is to verify. You will perform a follow-up experiment with the predicted best input settings to confirm if the results are correct.

The most important part of the learning process for DOE will be to implement the process. Find something you want to experiment on that is within cost and try it. If you decide to practice with pizza then you’ll have no shortage of quality control testers at your disposal.

How does one obtain a black belt?

I’ll assume you mean a Black Belt certification. This is a difficult question to answer and may sound vague, but I try to be as concise as possible. There is no real governing body for Six Sigma. Because of this there are wildly varying methods to get certified as a Black Belt with varying degrees of credibility. I realize that is not very helpful, but it is reality.

Before you decide on a certification body you need to ask yourself some questions:

  • What are your goals in certification? One major divergence is if you plan to apply the methods to manufacturing or to transactional endeavors. The gold standard certifying body for the practice of Six Sigma in manufacturing is the American Society for Quality.   They tend to approach Six Sigma from a purist perspective that is beneficial in a manufacturing environment. Most employers will accept the ASQ certification.
  • If your goal is to apply Six Sigma in the transactional world then there are more viable options. I would not suggest ASQ here since, in my opinion, you will need to approach Six Sigma as more of an art than a science in the transactional world. There are many bodies that provide certification. To weed out the good from the bad I would first find Black Belts and Master Black Belts that you would like to emulate and find out where they were certified. You will find that many were certified by a specific company that the worked for such as GE or Honeywell. If working for a company that provides a respected certification is not an option then I would consider a major university such as Villanova. I received both the Black Belt and Master Black Belt certificates from Villanova and was then granted practice privileges by my employer at each level. You must consider both the quality of the education and if a perspective employer respects the institution. Beware that most are not worth the money. I have not had much luck with Black Belts and Master Black Belts certified through; however the sample size was too small to be creditable. I have never been let down with the quality of Black Belts and Master Black Belts certified through Villanova.

What books should one read to become educated in the ways of Six Sigma?

I would first read books that help establish a baseline background and then branch as needed to gain additional information. Lean Six Sigma for Dummies is a great place to start. It does an excellent job of explaining the core concepts in simple terms. From there you can advance into deeper learning opportunities. Some that I would absolutely put on the list are:

  • The Toyota Way
  • The Lean Six Sigma Pocket Toolbook
  • Statistical Process Control Demystified
  • Process Mining by van der Aalst

Why should one put effort into getting six sigma certified?

Certification can be an excellent method to learn the basic concepts of Six Sigma. This will give you a baseline to work from to guide future learning and start developing the art of Six Sigma.

For a young practitioner a certification will prove that you have learned the underlying principles. It MIGHT help you clear the resume black hole that is the application process that we live in.

Think of a Six Sigma certification in the same way you would think of a college degree. The value you will get out of it will be a combination of the quality of the institution and your personal effort. Great effort can overcome the limitations of a poor institution and poor efforts will never be adequate even in a great institution.

What benefits come with being six sigma certified?

I am not saying this to be contrarian or to discourage you, but there are very few benefits of being certified. It may help you get in the door at a copany and it will possibly give some creditability, but your real value will be shown in your experience and your ability to apply the art of Six Sigma. Your portfolio of projects will have much greater benefit to both you and to potential employers.

Again this is the same as a college degree. You do not need a degree to become a Mark Zuckerberg or Bill Gates. I am not trying to argue against the validity of a college degree, but you truly do not need one for most professions if you can apply what you have learned. Despite that fact there is little downside to having a college degree or Six Sigma certification.

Does one need to become certified or just learn the six sigma process?

Learning the process will be much better than a certification in most circumstances. Your real value will come with experience and your ability to apply the methods. You may find, however, that gaining that experience without a certification will be difficult.   This will be especially true if you choose to pursue Six Sigma as a profession.

Overall I would say to trust your intuition if you are seeking a career outside of Six Sigma. For instance, if you want to apply the methods to engineering then you may only need to learn the process. The methods can improve the quality of work for nearly any profession. I will say, again, that I see no downside in becoming certified.


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