Category Archives for Six Sigma

Nonparametric Tests

Nonparametric Tests in Minitab

Before we talk about the Nonparametric Tests, let’s understand what Parametric Tests are.Parametric Tests:These are hypothesis tests that assume that the data being analyzed follows a distribution (generally Normal Distribution). Examples of Parametric Tests:One Sample z-TestTwo Sample z-TestOne Sample t-TestTwo Sample t-TestPaired t-Testetc.Nonparametric Tests:A nonparametric test does not assume anything about the underlying distribution. That way, […]

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Special Cause Vs Common Cause Variation

What is the variation?Whatever measurement we take, there is always a variation between these measurements. No two items or measurements are precisely the same. The problem with the variation is that it is the enemy of quality. Variation and quality do not go hand in hand. Variation reduction is one of the significant challenges of quality […]

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Best Six Sigma Certification

Six Sigma is a process improvement approach. Six Sigma was invented by Motorola way back in 1985. This approach has stood the test of time and is still widely used by organizations even after 35 years of its invention. This process improvement methodology can be used in any industry. The focus of Six Sigma is to […]

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Defects per million opportunities (DPMO)

In Six Sigma, Defects per Million Opportunities (DPMO) is the measure of the process performance. Defects per Million Opportunities (DPMO) Defect vs Defective: Defects per Unit: Defect Opportunity: Defect per Opportunity (DPO) Defect per Million Opportunities (DPMO) Sigma Level Defect vs Defective: Let’s first understand the difference between the defect and defectives.   Defect:   […]

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Six Sigma Certification – ASQ® or IASSC?

Many of my Six Sigma Green Belt and Six Sigma Black Belt students have asked me these questions: Which certification should I go for ASQ(American Society for Quality) or IASSC (International Association for Six Sigma Certifications)? Which of these to certificates is most valued – ASQ or IASSC? Let’s understand a few key facts before […]

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Common Probability Distributions

 1. Normal Distribution: ​Where: μ  = Meanσ  = Standard Deviation π ≈ 3.141e ≈ 2.718 ​2. Binomial Distribution: ​Where: p = Probability of successq = Probability of failure =  1−p​ n = Number of trialsP(x) = Probability of x successes in n trials ​3. Poisson Distribution: ​Where: m = Probability of successP(x) = Probability of […]

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Preventing Six Sigma Failure

Why do Six Sigma projects fail? When we say fail, we mean why the projects don’t achieve the objective which they were supposed to accomplish? There are various reasons for the project failure. However, the following are the top six reasons. 1. Lack of Management Support: The first reason or the prime reason for Six […]

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