Lessons in Quality During a Long and Strange Journey Home

I didn’t expect that our family trip to Florida would end with me driving a plane load of passengers nearly 200 miles to their homes, but it did.

Yes, it was a long and strange journey home. A journey that started in the tropical warmth of southern Florida and ended the next morning in central Pennsylvania, which felt like the arctic wastelands thanks to the dreaded polar vortex.

During this journey, I didn’t just experience temperature extremes, but also extremely different levels in the quality of customer care. Working at Minitab, I'm very aware of the quality of service because quality...

Applying Six Sigma to a Small Operation

Using data analysis and statistics to improve business quality has a long history. But it often seems like most of that history involves huge operations. After all, Six Sigma originated with Motorola, and became adopted by thousands of other businesses after it was adopted by a little-known outfit called General Electric.

There are many case studies and examples of how big companies used Six Sigma methods to save millions of dollars, slash expenses, and improve quality...but when they read about the big dogs getting those kind of results, a lot of folks hear a little voice in their heads...

Use the Minitab Assistant to Choose a Graph

Everyone loves Minitab’s Assistant. My favorite bit, as I’ve shown with the Gage R&R Study, is the way that the Assistant puts all the results you need into reports that are easy to understand and present. But it’s also pretty neat that before you ever choose what to do in Minitab, the Assistant is ready to help you. Let’s take a closer look at the Assistant's Graphical Analysis tools.

Help Me Choose

Choose Assistant > Graphical Analysis and the most prominent thing you’ll see is a question:

But you’re not left with just the three objectives. Select "graph variables over time," and before you...

Creating a Shatterproof Process: Students Use Six Sigma to Improve Window Manufacturing

I had the opportunity to speak with a great group of students from the New Jersey Governor’s School of Engineering and Technology—a summer program for high-achieving high school students. Students in the program complete a set of challenging courses while working in small groups on real-world research and design projects that relate to the field of engineering. Governor’s School students are mentored by professional engineers as well as Rutgers University honors students and professors, and they often work with companies and organizations to solve real engineering problems.

The team of students...

Quantum Estimates: Where Angels Fear to Tread

This close to the holidays, it’s hard to stay focused on work.

I should be writing a post about useful estimation tools for quality statistics. But all those yuletide carols about hosts of angels singing from on high have distracted me.

Alas, I’ve fallen into the clutches of one of the world’s oldest estimation problems, posed centuries ago by medieval scholars:

Just how many heavenly angels can dance simultaneously on the point of a pin?

The answer to this question assumes that you believe in the existence of pins, of course.

Estimation in the Middle Ages: Ask Your Doctor

Over the centuries, a...

Fix Problems in Regression Analysis with Partial Least Squares

Face it, you love regression analysis as much as I do. Regression is one of the most satisfying analyses in Minitab: get some predictors that should have a relationship to a response, go through a model selection process, interpret fit statistics like adjusted R2 and predicted R2, and make predictions. Yes, regression really is quite wonderful.

Except when it’s not. Dark, seedy corners of the data world exist, lying in wait to make regression confusing or impossible. Good old ordinary least squares regression, to be specific.

For instance, sometimes you have a lot of detail in your data, but not...

Regression Analysis Tutorial and Examples

I’ve written a number of blog posts about regression analysis and I think it’s helpful to collect them in this post to create a regression tutorial. I’ll supplement my own posts with some from my colleagues.

This tutorial covers many aspects of regression analysis including: choosing the type of regression analysis to use, specifying the model, interpreting the results, determining how well the model fits, making predictions, and checking the assumptions. At the end, I include examples of different types of regression analyses.

If you’re learning regression analysis right now, you might want to...

See How Easily You Can Do a Box-Cox Transformation in Regression

For one reason or another, the response variable in a regression analysis might not satisfy one or more of the assumptions of ordinary least squares regression. The residuals might follow a skewed distribution or the residuals might curve as the predictions increase. A common solution when problems arise with the assumptions of ordinary least squares regression is to transform the response variable so that the data do meet the assumptions. Minitab makes the transformation simple by including the Box-Cox button. Try it for yourself and see how easy it is!

The government in Queensland,...

Tooltips, Assistant Menu, and Help: The 5 Coolest Things You Didn't Know You Could Copy From Minitab

Minitab Statistical Software displays the information that you need in the analyses that you perform, but it’s possible that you might want to capture information in a different place, or even a different program, so that the results are as easy to communicate as possible. For those occasions, it’s helpful to know how to get text even from the less obvious places in Minitab. Here are five useful cases:

1. Boxplot Tooltips

In Minitab, you often can hover over part of a graph and get a yellow box with some text in it. Try this:

  • Choose File > Open Worksheet.
  • Click Look in Minitab Sample Data Folder.
  • Se...

The Value Stream Map: It's Been Around Longer than You Think

In looking for the answer to an unrelated quality improvement question the other day, I ran across a blog post that answers a question I'd had for a while: what's the origin of the value stream map? 

A value stream map (VSM) is a key tool in many quality improvement projects, especially those using Lean. The value stream is the collection of all of the activities, both value-added and non-value added, that generate a product or service that meets customer needs. The VSM shows how both materials andinformation flow as a product or service moves through the process value stream, helping teams...

Avoiding a Lean Six Sigma Project Failure, part 4

In my first post in this series, I mentioned that we reached out to our customers who are practitioners in the field of quality improvement to better understand how they complete projects, what tools they use, and the challenges and roadblocks they come across in achieving success with quality initiatives. One area quality leaders said they were struggling with was the training aspect of their programs—actually getting their belts and/or project team members up to speed with adequate training to complete projects independently.

Insufficient Training

They told us projects were failing because of...

Celebrating World Quality Month

It’s back! World Quality Month will be celebrated this month, and the American Society for Quality is again heading up this year’s festivities.

Quality is definitely our “thing” here at Minitab, and we’re excited to celebrate World Quality Month with quality professionals worldwide. It’s also a good time to remind our customers that we’re as dedicated as ever to providing the best tools for improving quality.

In honor of World Quality Month, be sure to check out the resources and learning opportunities available on Minitab.com:

Case Studies
We’re very proud to recognize the accomplishments of our...

Understanding ANOVA by Looking at Your Household Budget

by Arun Kumar, guest blogger

One of the most commonly used statistical methods is ANOVA, short for “Analysis of Variance.” Whether you’re analysing data for Six-Sigma styled quality improvement projects, or perhaps just taking your first statistics course, a good understanding of how this technique works is important.

A lot of concepts are involved in any analysis using ANOVA and its subsequent interpretation. You’re going to have to grapple with terms such as Sources of Variation, Sum of Squares, Mean Squares, Degrees of Freedom, and F-ratio—and you’ll need to understand what statistical...

Applied Regression Analysis: How to Present and Use the Results to Avoid Costly Mistakes, part 2

Applied regression analysis can be a great decision-making tool because you can predict the average outcome given input values. However, predictions are not as simple as plugging numbers into an equation. In my previous post I showed how a majority of experts vastly underestimated the variability around the predicted outcome in a manner that can lead to costly mistakes.

We also saw how graphing the data is a simple way to avoid these mistakes because it highlights the uncertainty. In this post, I'll explore other techniques that you can use in Minitab statistical software to facilitate good...

The Three Coolest Things You Didn't Know about Histograms in Minitab

Not too long ago, I observed that one number is rarely adequate to describe data. Means and medians can disagree, and it’s important to know whether different groups of data have similar spreads. A great tool for displaying a more complete representation of the data is the histogram. Histograms are an easy way to summarize a lot of statistics. If you’re not convinced, take a minute to explore some. For example, Katherine Roswell can give you an example of how to use a histogram to identify the best opportunity for improvement in hospital patient readmissions. Histograms are great.

And the...

How Data Analysis Can Help Us Predict This Year's Champions League

by Laerte de Araujo Lima, guest blogger

A few weeks ago, my football friends and I were talking about the football in the UEFA Champions league (UEFA CL), and what we could expect for the 2013-14 season.

Some of us believe that the quality of the football played in the UEFA CL has improved in the last few years, as evidenced by more goals per match, more teams with strategies based in the attack and, finally, more show games. Others disagree, arguing that the teams were pursued defensive strategies with consequently fewer goals per match, more faults per game, and less effective use of game time...

Debt Made Beautiful

Does the prospect of a looming U.S. government shutdown depress you? 

Are you tired of the ongoing game of Chicken played over our federal budget? The dissonant hysterics of deficit drama queens? The glib arrogance of deficit deniers?

Then it might be a good time to take a break and focus on something more pleasant. Something you can control. Something you can improve and make more beautiful.

Like editing your graphs in Minitab.

In this post, I'll show you how to gussy up a graph with a few simple maneuvers.

(If you want to follow along and you don’t have Minitab 16, download a free trial copy.)


Applied Regression Analysis: How to Present and Use the Results to Avoid Costly Mistakes, part 1

Imagine that you’ve studied an empirical problem using linear regression analysis and have settled on a well-specified, actionable model to present to your boss. Or perhaps you’re the boss, using applied regression models to make decisions.

In either case, there’s a good chance a costly mistake is about to occur!

How regression results are presented can lead decision-makers to make bad choices. Emre Soyer and Robin M. Hogarth*, who study behavioral decision-making, found that even experts are frequently tripped up when making decisions based on applied regression models.

In this post, I'll look...

Using Prediction Intervals to Define Process Windows

Making parts that are truly interchangeable is a critical aspect of modern manufacturing. The same parts may be manufactured in different plants spread around the globe or by suppliers located far away. Parts need to be manufactured to specifications to ensure that they are almost identical to allow an easy assembly of new products.

Interchangeability is increasingly important in the service industry as well. Because customers expect similar standards from a service company wherever it does business around the globe, best practices need to be deployed throughout a company and...

Itchy, Sneezy, Stuffy: Delivering Relief with Nasal Spray and DOE

Recently, a customer called our Technical Support team about a Design of Experiment he was performing in Minitab Statistical Software. After they helped to answer his question, the researcher pointed our team to an interesting DOE he and his colleagues conducted that involved using nasal casts to predict the drug delivery of nasal spray.

The study has already been published, and you can read more about it here, but I wanted to highlight this use of the DOE tools in Minitab in this blog post.

Using Nasal Casts to Predict Nasal Spray Drug Delivery

The nose is a convenient route of administration...