What is Statistical Distribution in Six Sigma?
Distribution is the statistical term that describes the relative likelihood of observing values for a variable factor. When you think of a Six Sigma initiative and the critical performance characteristics [more…]
How to Construct and Interpret a Multi Vari Chart for a Six Sigma Initiative
You don’t have to wait until your multi-vari data are collected to start creating the multi-vari chart for Six Sigma. Instead, you can build the chart, incrementally, adding more to it as you collect more [more…]
What is Short Term Variation in Six Sigma?
When enacting a Six Sigma initiative, you will undoubtedly encounter short term variation. Short-term variation is purely random. Like rolling a pair of dice, you can’t predict what the next output value [more…]
What is Long Term Variation in Six Sigma?
You will need to understand long term variation to launch a successful Six Sigma initiative. When underlying disturbances are added to the natural short-term variation, the overall combination is called [more…]
How to Create and Interpret Dot Plots and Histograms in a Six Sigma Project
Both dot plots and histograms give you lots of information about the variation of a critical characteristic in a process for a Six Sigma initiative. A [more…]
How to Create and Interpret Box and Whisker Plots for a Six Sigma Project
Like putting two people back-to-back to see who’s taller, Sigma Six uses box and whisker plots (or just box plots) to directly compare two or more variation distributions. When you need to compare value [more…]
How to Draw Correlations from Scatter Plots in Six Sigma Analysis
A scatter plot tells you graphically how two characteristics are related, or correlated in a Six Sigma initiative. You can then use this correlation information to explore which factors and outputs affect [more…]
How to Use the Central Limit Theorem for Six Sigma
What happens when you take repeated samples from the same population? This idea is important when you use the central limit theorem for Six Sigma. Imagine flipping a coin ten times and counting the number [more…]
How to Use the Confidence Intervals for Six Sigma
Because samples are accessible, samples and confidence intervals are the primary data tool for understanding a business or processing Six Sigma performance situations. But samples can never give you an [more…]
How to Use the Confidence Intervals for Proportions in Six Sigma
Sometimes in a Six Sigma project, you will be faced with confidence intervals and proportions. When you calculate the number of successes out of a certain number of attempts — like “four out of five dentists [more…]
What You Should Know about 2k Experimentation for Six Sigma
2k full factorial experiments give you a powerful jump-start into the world of improvement through DOE for Six Sigma projects. But really, they’re just the tip of the iceberg. As you gain experience, you [more…]
How to Set Standards for Six Sigma
Taking measures for Six Sigma projects to enable and encourage a process to follow a standard — a standard sequence, a standard method of handling, a standard set of equipment settings, and so on — must [more…]
How to Detect Patterns in Control Charts for Six Sigma
Besides control chart points that lie beyond the control limits in Six Sigma, other visual patterns can tell you that something out of the ordinary is happening to your process. These other patterns also [more…]
How to Collect Data for Control Charts for Six Sigma
You must collect data for control charts for Six Sigma projects in a way that avoids a distorted or inaccurate view of the process performance — whether overly optimistic or too bleak. Using rational subgroups [more…]
How to Make Control Charts for Attribute Data for Six Sigma
In Six Sigma initiatives, you can make control charts for attribute data. Attribute data is data that can’t fit into a continuous scale but instead is chunked into distinct [more…]
What is Six Sigma?
It’s okay if you don’t know what Six Sigma is at all, or don’t understand every aspect of it. That’s because Six Sigma — once a precise, narrowly-defined term — has grown over time to represent a number [more…]
The Managerial Perspective of Six Sigma
Six Sigma action occurs on two levels: the managerial and the technical. At the managerial level, a Six Sigma initiative includes many units, people, technologies, projects, schedules, and details to be [more…]
Management System Orientation for Six Sigma
Six Sigma is so appealing to managers because it delivers business management results. Managers need to see a return on investment, commitment, accountability, transparency, and a clear path to success [more…]
What is Quality in Six Sigma?
To begin understanding the technical side of Six Sigma, you have to first answer a seemingly straightforward question: What is quality? A traditional and widely held definition of quality is [more…]
The Six Sigma Perspective on Quality
What’s poor quality really costing your business? Compare the flawed traditional perspective and the Six Sigma perspective on specifications and their relation to quality and costs. Poor quality is detrimental [more…]
How to Connect Quality to Variation with Six Sigma
Simply changing a company’s belief system — its philosophy — from a goal post quality mentality to a Six Sigma “on target with minimal variation” mentality immediately and naturally begins to alter the [more…]
How Much Statistical Skill Is Required for Six Sigma?
Solving problems the Six Sigma way requires varying degrees of skill in applied statistics. Solving complex problems requires considerable statistical expertise, but dealing with moderate problems or routine [more…]
How to Launch a Six Sigma Project
In Six Sigma, you make progress the old-fashioned way — one project at a time. In essence, projects are the unit of change; they define the collective effort by which most Six Sigma progress is accomplished [more…]
How to Decide if a Six Sigma Project is Worthwhile
After you set the targeted level of improvement, you can then determine the financial benefit of doing the Six Sigma project and decide whether the project is worth your time. The Six Sigma effort is often [more…]
How to Write a Problem Statement for Six Sigma
The problem statement serves several purposes in a Six Sigma project. First, it significantly clarifies the current situation by specifically identifying the problem and its severity, location, and financial [more…]
