Six Sigma | Intro to six sigma

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Hello guys,

Here we will learn the background and meaning of Six Sigma (6σ) to get basics of six sigma. We will learn,

Understand the Six Sigma methodology.
Six Sigma approach
DMAIC process improvement cycle
Six Sigma problem solving strategy

Now, most of you are probably already familiar with Six Sigma and we want this article to supports you, either to refresh your knowledge.

“The Six Sigma system is a comprehensive and flexible system for
achieving, sustaining and maximizing business success.”

Pande, P. S., R. P. Neuman, and R. L. Cavanagh. 2000.
The Six Sigma Way. New York, NY: McGraw-Hill.

There may be occasional failures in driving toward perfection, but a Six Sigma organization will not be deterred by these, they’ll learn from their failures and make progress towards perfection. The Six Sigma process strive to achieve this, by careful understanding of customer needs, use of facts through data collection and statistical analysis, and by managing, improving and re-engineering production, as well as  business processes, to increase customer satisfaction and business excellence. And hereby, business excellence we’re talking about, Cost Reduction, Productivity improvement, growth of market share, customer retention cycle, time reduction defect reduction and change to quality culture, in new product and service development.

Understand the Six Sigma methodology

So, let’s look a little bit at the origins, and the development of Six Sigma. In the late 1970’s, Motorola started experimenting with problem solving, through statistical analysis and started using the Six Sigma approach in the 1980’s, to achieve one of its top corporate goals of improving quality. The engineer Bill Smith, called the father of Six Sigma. With Dr. Mikel Harry, who was responsible for the development of the Six Sigma implementation strategy and guideline deployment, Six Sigma was implemented at Motorola and in 1990’s, Dr. Harry founded and directed Motorola six Sigma Research Institute.

In 1987, it was the official birth of the Six Sigma Motorola methodology in Motorola and this is for the communication sector uses an approach to track and compare performance, against the customer requirements and to achieve the target. And the key is that the defect rate for the production of each component, will not be more than 3.4 defects per million. Then they received the prestigious national award, the Malcolm Baldrige award for Business Excellence in 1988. In the ten years between 1987 and 1997, the company increased its sales, saved billion’s from Six Sigma projects. But, what does this 3.4 defects-per-millions,

Let’s look at a few terms from Six Sigma (6 σ ), first of all, The term Sigma ( σ ) is used to designate the distribution or spread from the mean, the average of any process or procedure for process is the Sigma capability. The higher the Sigma capability, the better the process, to produce defect free outputs. A defect is anything that results in customer dissatisfaction, we are defining it as a defect occurs during any process step, when the outcome of the process step is not the expected outcome and that means we have defined the expected outcome in advance.

Six sigma approach

  • Focus on the Customer
  • Data and Fact-Driven Management
  • Process Focus
  • Proactive Management
  • Drive for Perfection (with tolerance for failure)

DMAIC process improvement cycle

The Six Sigma system recommends a five-step problem-solving methodology or five step road map, for organizations that want to become a Six Sigma organization, therefore this process improvement cycle uses the sequence define, measure, analyze, improve and control, which is abbreviated as DMAIC. Now, we’re going to go through the DMAIC flow in detail.

Define: means to identify key customer requirements, what we call the critical to quality parameters. We want to set the goals for the Six Sigma project and form the project team.

Measure: you need to be able to map the process that we’re studying. We want to collect data, determine the current process performance and the current process capability. We measure influencing parameters, those that are likely to impact our critical to quality parameters.

Analyze: we need to analyze all of the data, we need to confirm what we call the vital few determinants of the performance. These are the key influencing parameters that affect our critical to quality outputs. We want to establish hypotheses for improvement & cause analysis.

Improve: you want to validate these hypotheses and you want to develop ideas to remove root causes, design and carry out experiments, to optimize the process, and finally, establish a solution for the process improvement.

Control: finally you establish a monitoring for your process, for these influencing parameters and you use generally statistical process control (SPC).

Six Sigma problem solving strategy

We now want to review the Six Sigma roadmap and the overall problem solving strategy used in Six Sigma. So we have our equation,

Y =f(x)
Y(CTQ) =f(all possible X-Influencers)

 Y is a function of X, this is the fundamental equation behind the Six Sigma application strategy so the letter Y here is represents the output or critical to quality parameters of the customer values. Whereas the letter X, are the parameters of influence or affect the ‘Y’s, the object is to move from the left side to the right side of the equation.

Our goal is to obtain knowledge about the ‘Y’s and the ‘X’s, as we move from process characterization, to process optimization and we achieve this goal, by following the road map.

We take the project through the five phases; define, measure, analyze, improve and control. Now, in

  • define; where
    • we come up with our project charter,
    • build our team,
    • listen to the voice of the customer,
    • understand what the critical to quality ‘Y’s are,
  • then in measure; you’re
    • looking at measuring, mapping the process,
    • measuring those parameters and starting at the top of our funnel.
    • Looking at the overall capability of our process.
  • Then we move through analyze; we
    • narrow down these many ‘X’s to a vital few,
    • we do cause and effect analysis,
    • we identify the critical access and their influence on the Y with design of experiments or regression for example.
  • And finally, improve;
    • we improve our process,
    • test these improvements, and at the very end,
    • under control; we put controls in place, for the critical influencing X variables using as we said, SPC.