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Tips and Techniques for Statistics and Quality Improvement

Blog posts and articles about using Minitab software in quality improvement projects, research, and more.

Many things have shocked me since having my first baby back in August. I didn’t think it was possible to be so tired that it actually hurt, and I also didn’t think that changing 10+ diapers a day would actually be the norm (or that needing to perform 10+ outfit changes was even possible, let alone necessary). I also didn’t think that we’d fall in love so hard with the little guy. What a wonderful,... Continue Reading
by Lion "Ari" Ondiappan Arivazhagan, guest blogger.  An alarming number of borewell accidents, especially involving little children, have occurred across India in the recent past. This is the second of a series of articles on Borewell accidents in India. In the first installment of the series, I used the G-chart in Minitab Statistical Software to predict the probabilities of innocent children... Continue Reading
As I’m sure you’ve heard by now, Kentucky is really good at basketball. They're the only team in the country without a loss, and they have a realistic shot at becoming to first team to win the championship with an undefeated record since the 1976 Indiana Hoosiers. Under any ranking system you want to use, Kentucky is clearly the #1 team in college basketball. Well, almost any ranking system. All... Continue Reading
In my previous post, I showed you how to set up data collection for a gage R&R analysis using the Assistant in Minitab 17. In this case, the goal of the gage R&R study is to test whether a new tool provides an effective metric for assessing resident supervision in a medical facility.   As noted in that post, I'm drawing on one of my favorite bloggers about health care quality, David Kashmer of the... Continue Reading
One of my favorite bloggers about the application of statistics in health care is David Kashmer, an MD and MBA who runs and writes for the Business Model Innovation in Surgery blog. If you have an interest in how quality improvement methods like Lean and Six Sigma can be applied to healthcare, check it out.  A while back, Dr. Kashmer penned a column called "How to Measure a Process When There's... Continue Reading
Right now I’m enjoying my daily dose of morning joe. As the steam rises off the cup, the dark rich liquid triggers a powerful enzyme cascade that jump-starts my brain and central nervous system, delivering potent glints of perspicacity into the dark crevices of my still-dormant consciousness. Feels good, yeah! But is it good for me? Let’s see what the studies say… Drinking more than 4 cups of coffee... Continue Reading
Juvenile Idiopathic Scoliosis. That was the diagnosis given to my then 8 year old daughter last January. In short, it means that she’s young (under 10), she exhibits an abnormal amount of spinal curvature, and there’s no identified cause (aside from some bad luck). Emilia’s x-rays indicated an S-shaped curve with 26 degrees at its largest curvature. To look at my healthy, active daughter, you’d... Continue Reading
In technical support, we often receive questions about Gage R&R and how Minitab calculates the amount of variation that is attributable to the various sources in a measurement system. This post will focus on how the variance components are calculated for a crossed Gage R&R using the ANOVA table, and how we can obtain the %Contribution, StdDev, Study Var and %Study Var shown in the Gage R&R output. ... Continue Reading
It’s safe to say that most people who use statistics are more familiar with parametric analyses than nonparametric analyses. Nonparametric tests are also called distribution-free tests because they don’t assume that your data follow a specific distribution. You may have heard that you should use nonparametric tests when your data don’t meet the assumptions of the parametric test, especially the... Continue Reading
In part 1 of this post, I covered how Six Sigma students at Rose-Hulman Institute of Technology cleaned up and prepared project data for a regression analysis. Now we're ready to start our analysis. We’ll detail the steps in that process and what we can learn from our results. What Factors Are Important? We collected data about 11 factors we believe could be significant: Whether the date of... Continue Reading
Over the weekend Penn State men's basketball coach Pat Chambers had some strong words about a foul that went against his team in a 76-73 loss against Maryland. Chambers called it “The worst call I’ve ever seen in my entire life,” and he wasn’t alone in his thinking. Even sports media members with no affiliation to Penn State agreed with him. This wasn't the first time this season Chambers has... Continue Reading
By Peter Olejnik, guest blogger. Previous posts on the Minitab Blog have discussed the work of the Six Sigma students at Rose-Hulman Institute of Technology to reduce the quantities of recyclables that wind up in the trash. Led by Dr. Diane Evans, these students continue to make an important impact on their community. As with any Six Sigma process, the results of the work need to be evaluated. A... Continue Reading
I left off last with a post outlining how the Six Sigma students at Rose-Hulman were working on a project to reduce the amount of recycling thrown in the normal trash cans in all of the academic buildings at the institution. Using the DMAIC methodology for completing improvement projects, they had already defined the problem at hand: how could the amount of recycling that’s thrown in the normal trash... Continue Reading
If you wanted to figure out the probability that your favorite football team will win their next game, how would you do it?  My colleague Eduardo Santiago and I recently looked at this question, and in this post we'll share how we approached the solution. Let’s start by breaking down this problem: There are only two possible outcomes: your favorite team wins, or they lose. Ties are a possibility,... Continue Reading
I typically attend a few Lean Six Sigma conferences each year, and at each there is at least one session about compensating belts. Any number of ideas exist out there, but they commonly include systems that provide a percentage of savings as a portion of pay or provide a bonus for meeting target project savings. There are always issues with these pay schemes, including the fact that... Continue Reading
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! My LSS coach suggested that I regularly conduct data analysis to refresh my Minitab... Continue Reading
  In my experience, one of the hardest concepts for users to wrap their head around revolves around the Power and Sample Size menu in Minitab's statistical software, and more specifically, the field that asks for the "difference" or "difference to detect."  Let’s start with power. In statistics, the definition of power is the probability that you will correctly reject the null hypothesis when it is... Continue Reading
Recently, Minitab’s Joel Smith posted about his vacation and being pooped on twice by birds. Then guest blogger Matthew Barsalou wrote a wonderful follow-up on the chances of Joel being pooped on a third time. While I cannot comment on how Joel has handled this situation psychologically so far, I can say that if I had been pooped on twice in a short amount of time, I would be wary of our... Continue Reading
As someone who has collected and analyzed real data for a living, the idea of using simulated data for a Monte Carlo simulation sounds a bit odd. How can you improve a real product with simulated data? In this post, I’ll help you understand the methods behind Monte Carlo simulation and walk you through a simulation example using Devize. What is Devize, you ask? Devize is Minitab's exciting new,... Continue Reading
There’s no shortage of interest this week in whether Tom Brady is the best quarterback to ever play the game of football. As a University of Tennessee alum, I have to recuse myself from that particular debate for lack of objectivity. (Everyone knows Peyton Manning is the best quarterback to ever play the game, right?) But now seems like a good time to look at some numbers that show where Brady... Continue Reading