Six Sigma

Six Sigma (6S) is the gold standard for business management in the manufacturing industry. Its a toolkit of brainstorming, team management, and decision making techniques approach a problem.

I heard of this methodology in career panels and job listings, and thought it was a super technical certification that only advanced engineers earned. The more I learned about it, the more I realized it was just a logical mindset for solving problems; both in industry and everyday life.

In a manufacturing engineer interview, the managers usually give a generic white-board problem. They actually won’t care about the solution as much as the methodology used to find them. If you use buzzwords like “Fishbone”, “5 Whys”, or “Is-Not”, you’ll earn massive brownie points with the interviewers. It’ll show that you’ve done your homework about the position, and have the right attitude for the plethora of problems the job entails.

The Meaning of Six Sigma

If you’re familiar with statistics, then you’d recognize that “standard deviations” are represented by the Greek letter sigma: σ.

The standard deviation equation is the squared differences between each sample (x_i) from the average (x bar).

That scary equation just calculates how spread out each measurements is from the average. So, a larger standard deviation means the measurements are more spread out. Most things in life we would prefer to have small standard deviations.

• If a friend told you they were coming over at 8 PM, would you prefer knowing if they were to arrive between:
  • 7:50 PM to 8:10 PM, or
  • 2:00 PM to 2:00 AM?
• If a car is supposed to last 200,000 miles, would you prefer knowing if it were accurate within:
  • 190,900 to 200,100 miles, or
  • 100,000 to 300,000 miles?
• If you order of a 12-piece chicken nuggets, would you prefer receiving within:
  • 11 to 13 nuggets, or
  • 5 to 19 nuggets?

These examples show low and high ranges from the expected value.
With high variance, it’s a gamble between: being thrilled with this extra value, or being frustrated with a faulty product. We prefer predictability in our lives, since it helps provide us some control and structure.

The Customer is Right

Customers expect to get exactly what they pay for.
A single unsatisfactory product could permanently ruin a company’s reputation; a man that receives 5 nuggets would never return again, and take every opportunity to slander the restaurant with awful 5-nugget experience.

Customers expect to get exactly what they pay for.
A single unsatisfactory product could permanently ruin a company’s reputation; a man that receives 5 nuggets would never return again, and take every opportunity to slander the restaurant about his awful 5-nugget meal.

Six Sigma (6S) is thus titled after keeping values within three standard deviations of the specification. A 6S process capability describes a process that only fails 3.4 parts per million; a 99.9997% success rate. To summarize:

Six Sigma reduces variation to consistently meet requirements

How to reach Six Sigma?

There are countless, free online resources to learn about the Six Sigma process. But to be officially “Six Sigma Certified” you have to pay a couple thousand dollars from an accredited 6S program, and then provide evidence that you were involved in an actual 6S project within the industry environment.

The ranks are like karate:

1. White Belt: Basic understanding and awareness of 6S
   • Technicians
2. Yellow Belt: Participates in 6S projects during reviews
   • Entry-level engineers
3. Green Belt: Participates in 6S projects, and may lead smaller projects
   • Mid-level engineers
4. Black Belt: Leads major 6S projects; trains and coaches the Green Belts
   • Senior engineers, managers
5. Master Black Belt: Trains & coaches both Black and Green Belts
   • Senior managers, directors

Ok, ok, but what is Six Sigma, really?

Alright, so 6S problem solving revolves around DMAIC methodology. Returning to the “Six Sigma” name, the methodology requires statistical data to drive from problem states to corrected states.

• Define: What is the problem statement?
• Measure: What is the measurement of success?
• Analyze: What is the root cause of the problem?
• Improve: What action will correct the root cause?
• Control: How will this change be monitored and verified?

A good way to grasp DMAIC is to apply them to everyday issues.
Check out this example to get started

Accredited 6S Programs

These associations actually serve as a host for 6S-certified training programs offered either in-class or online. It is costly to pay out-of-pocket for certifications; if there’s an opportunity to take it within university or sponsored by the company, take it!

• American Society for Quality (ASQ)
• International Association for Six Sigma Certification (IASSC)