Has it happened to you?  

You organize a brainstorming session to begin analyzing your process.

At the kick-off meeting, several people sit with arms crossed, lips pursed, eyes cast downward. Frequently, they’re the ones who’ve worked at the process for most of their professional lives.

“Here we go again. Wasting time to prove the obvious,” their faces say. “I’ve done my job for years. You’re not going to show me anything I don’t already know.”

Yet you bravely push forward. Every now and then you see someone roll their eyes. “When can I get back to my desk and do some real work?!!!”  they seem to...

by Matthew Barsalou, guest blogger

In my last post, I shared my plans for building a simple do-it-yourself catapult for performing experiments to practice using design of experiments (DOE). 

That's the completed catapult there on the right. If you want to build your own, here are my plans and instructions in a PDF.  

Now that my catapult is built, I have one last step to complete:  to find the optimal catapult setting using DOE, which I'll do with Minitab Statistical Software. (If you'd like to follow along but don't already have it, please download the 30-day free trial of Minitab.) 

Planning...

In honor of the International Year of Statistics, I interviewed Scott Pammer, a technical product manager here at Minitab Inc. in State College, Pa. Scott works to develop new product concepts and the accompanying prototypes and business plans.

Before taking on the role of technical product manager, Scott worked for Minitab as a senior statistician. In this role, he designed and programmed various features in Minitab Statistical Software. He’s been with Minitab since 1995.

What was your journey to becoming a statistician?

When I was a senior in high school, I knew I needed to pick a college...

While value stream mapping, or VSM, is a key tool used in many Lean Six Sigma projects for manufacturing, it’s also widely used in healthcare.

Value stream mapping can help you map, visualize, and understand the flow of patients, materials (e.g., bags of screened blood or plasma), and information. The “value stream” is all of the actions required to complete a particular process, and the goal of VSM is to identify improvements that can be made to reduce waste (e.g., patient wait times).

How is VSM applied to healthcare?

When used within healthcare, one obvious application for VSM is mapping a...

One of the most poorly understood concepts in the use of statistics is the idea of assumptions. You've probably encountered many of these assumptions, such as "data normality is an assumption of the 1-sample t-test."  But if you read that statement and believe normality is a requirement of the 1-sample t-test, then you have missed a subtle and important characteristic of assumptions and need to read on...

An "assumption" is not necessarily a "requirement"!

To understand where this idea of assumptions come from, let's forget about statistics for a minute and imagine we sell bikes online.  We...

by Matthew Barsalou, guest blogger

For want of a nail the shoe was lost,
For want of a shoe the horse was lost,
For want of a horse the rider was lost
For want of a rider the battle was lost
For want of a battle the kingdom was lost
And all for the want of a horseshoe nail. (Lowe, 1980, 50)

According to the old nursery rhyme, "For Want of a Nail," an entire kingdom was lost because of the lack of one nail for a horseshoe. The same could be said for the Galactic Empire in Star Wars. The Empire would not have fallen if the technicians who created the first Death Star had done a proper Failure Mode and...

In my last post, we talked about using statistical tools to identify the right distribution of our lightsaber manufacturing data. Now that we have our data in Minitab along with a specific distribution picked out, we can find out if we are dealing with an in-control process. If the process is not in control, the capability estimates will be incorrect. Thus, an extremely important (and often overlooked) aspect of Capability Analysis is to make sure our process in first in control. We can do this with a tool Minitab Statistical Software offers called the Capability Sixpack.TM

First, let’s go to S...

  Lionel Loosefit has been hauled to court for violating the assumptions of regression analysis. On the last day of the trial, the prosecution and defense present their closing arguments. And the fate of Mr. Loosefit is decided by judge and jury...

The Prosecution's Summary

Prosecutor: Ladies and gentlemen, we’ve presented a slew of evidence in this trial. You’ve seen, with your own eyes, every possible heinous violation of the assumptions for regression in the defendant’s model. Here’s what we’ve shown, in a nutshell:

Prosecutor: We’ve carefully delineated each violation with specific graphic...

Various commercials valiantly vied for the attention and dollars of football Super Bowl commercial fans on Sunday. The game was decided objectively (or by the referees), but the drama of which commercials won lives on. Because we love data analysis, I gathered a little bit to see which efforts really stood out. Then I plotted the data in Minitab to explore the results.

Three top-ten lists attracted my attention:

• True Reach by Visible Measures: The number of views on any website
• bluefin labs: The number of mentions on Twitter and public Facebook comments
• TiVo Rank: The rank for the number of...

Measurement systems analysis (MSA) is essential to the success of any data analysis. If you cannot rely on the tool you’re using to take measurements, then why bother collecting data to begin with? It would be like trying to lose weight while relying on a scale that doesn’t work. What’s the point in weighing yourself?

Minitab Statistical Software offers many types of tools that you can use to assess your measurement system, including:

• Gage R&R Study (Crossed)
• Gage R&R Study (Nested)
• Attribute Agreement Analysis

Destructive Testing Defined

In MSA studies for continuous measurements (e.g. weight,...

Recap: Lionel Loosefit has been arrested and hauled to court for violating the assumptions of regression analysis. In the previous court session, the prosecution presented evidence to show that the errors in Mr. Loosefit’s model were not normally distributed. Today, the prosecution addresses the second alleged violation: namely, that the errors in the defendant’s regression model are not independent. Dr. Minnie Tabber, a world-renowned statistician, is on the witness stand.

Prosecutor: Let me remind the members of the jury that a residual is simply the difference between the data value...

In my previous post, you learned how to prepare your data for capability analysis in Minitab. Now let's see where we need to go in the statistical software to run the correct Capability Analysis.

When it comes to capability analysis, Minitab offers a few different choices. We offer Normal Capability Analysis for when your data follow a normal distribution. If your data follow a different distribution, such as the Weibull distribution, there's Non-normal Capability Analysis. We also offer Binomial Capability and Poisson Capability for when you are looking to produce a process capability report...

In the past couple of years, I've noticed a new acronym popping up across the Web. In case you've not yet encountered it, "FML" typically appears in social media updates about something gone awry.  As in, "The cat ate my homework. FML!"  Or, "My production line just broke down, and now the company is going to be short on a major order. FML!" 

This acronym reminds me of an abbreviation used in Lean Six Sigma and quality improvement: FMEA.  It's short for "Failure Modes and Effects Analysis," which basically means "look very, very carefully at how and why stuff can go wrong."

FMEA: Failure Modes...

by Matthew Barsalou, guest blogger

In Jim Frost’s article “How to Be a Ghost Hunter with a Statistical Mindset,” he correctly pointed out the difficulties in distinguishing small effects from natural variation. However, he did not mention the benefits of doing measurement system analysis (MSA) in both ghost hunting as depicted by his example and in the statistical study using Minitab.

In industrial settings, testing equipment is evaluated to determine if the device used to assess the factor being studied is taking accurate measurements. In other words, are you collecting data that you can...

Before I started studying statistics, references to a mysterious "Monte Carlo Method" made it seem like the most cryptic thing in the data-analysis universe. People were developing programs dedicated solely to Monte Carlo, and offering special workshops and seminars. It seemed so great and terrible that someone like me—mere mortal that I am—would never be able to understand it. 

Fast-forward a few years, and now that I have some experience with it, I'm wondering why Monte Carlo has the reputation it does. The fact of the matter is, at least from a data analysis perspective, Monte Carlo...

If you’re looking to save some time while using Minitab Statistical Software, check out these tips for setting default options.

What Are the Options in My Statistical Software?

Options are default Minitab settings that you use each time that you create a graph or conduct an analysis. Some options are global in nature (What color would you like your graphs to be?), while others pertain only to certain graphs or tests (What tests should I perform when I create control charts?).

Some options have the effect of selecting items for you as you create a graph or perform an analysis, thereby saving you...

Bailiff: All Rise. The Honorable Judge Lynn E. R. Peramutter presiding.

Judge: Please be seated. Bailiff, please read the charges.

Bailiff: Your honor, this is the case of the State vs. Lionel Loosefit. The defendant is charged with creating a model that violated the legal requirements for regression. The infractions include:

• Producing grossly nonnormal errors
• Producing errors that lack independence
• Exhibiting nonconstant variance
• Violating the linearity assumption

Judge: Thank you, bailiff. Let’s hear the opening statement by the prosecutor.

Prosecutor: Your honor, ladies and gentlemen of the jury....

Marlowe the Stats Cat here. Earlier, I showed you how easy it was to set up my statistical software with a personalized menu of statistical tools I use most often. 

The problem is that I share a computer with one of the humans who live in my house, and the statistical tools I use most may not be the ones he needs to use. And I don't want to clutter myinterface with a "Human" menu.    I'm trying to be kind, but I should just be direct about this: as a cat, I have abilities that far oustrip those of my human. That extends to the range of statistical tools I can use effectively.   What I need to...

Recently I've been refreshing my knowledge of reliability analysis, which is the use of data to assess a product's ability to perform over time. Quality engineers typically use reliability analysis to predict the likelihood that a certain percentage of products will fail over a given amount of time.   

Statistical software will do the calculations involved in a reliability analysis, but there's a catch: first, you must choose a distribution to model your data. Put plainly, you need to tell the software to base its analysis on the normal distribution, the Weibull distribution, or perhaps some...

The Minitab Fan section of the Minitab blog is your chance to share with our readers! We always love to hear how you are using Minitab products for quality improvement projects, Lean Six Sigma initiatives, research and data analysis, and more. If our software has helped you, please share your Minitab story, too!

Growing up, I had little or no interest in math. In Africa we had little or no manufacturing; therefore, I had no idea about manufacturing processes, quality improvement, and so on. There was nothing there to motivate me play with numbers. I used to be terrified to see charts and...