Tips and Techniques for Statistics and Quality Improvement

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

This week is the annual Thanksgiving holiday in the United States, a period where we are encouraged to eat turkey and cranberries, then consider the blessings in our lives before falling into a comfortable pre-football nap. That includes many of us here at Minitab.  Consequently, we won't have new posts for you over the next two days.  But one of the things I'm grateful for is having had the... Continue Reading
This past weekend in the Big Ten showed how being conservative on 4th down decisions can cost you a game. Ohio State punted on 4th and 1 three different times, while Penn State and Illinois both kicked field goals in the 4th quarter when they needed a touchdown to tie or take the lead. All three teams lost. Perhaps taking some advice from the 4th down calculator would have greatly benefited them! If... Continue Reading
Reliability and survival analysis is used most frequently in manufacturing. Companies use these methods to estimate the proportion of units that will fail within, or survive beyond, a given period of time. But could these reliability and survival analysis techniques prove useful in a zombie apocalypse, too? Today's blog post explores that chilling scenario.  Think. This is what Zachary is telling... Continue Reading
Back when I was an undergrad in statistics, I unfortunately spent an entire semester of my life taking a class, diligently crunching numbers with my TI-82, before realizing 1) that I was actually in an Analysis of Variance (ANOVA) class, 2) why I would want to use such a tool in the first place, and 3) that ANOVA doesn’t necessarily tell you a thing about variances. Fortunately, I've had a lot more... Continue Reading
According to this article published on Food Tank, over 22 million pounds of food is wasted on college campuses each year. Now that’s a lot of food waste! Students all over the country are noticing excessive food waste at their schools and are starting programs to bring awareness and improve the problem. Naturally, many of these programs have roots in Lean Six Sigma. In one example, a group of... Continue Reading
We use statistics to arm ourselves with more information. That information allows us to make more informed decisions. And the sooner we can obtain this information, the better. For example, suppose one of your manufacturing machines starts to malfunction and makes your products out of spec. You don't want to wait until the product reaches customers before you discover this information. Then it's... Continue Reading
Did you ever wonder why statistical analyses and concepts often have such weird, cryptic names? One conspiracy theory points to the workings of a secret committee called the ICSSNN. The International Committee for Sadistic Statistical Nomenclature and Numerophobia was formed solely to befuddle and subjugate the masses. Its mission: To select the most awkward, obscure, and confusing name possible... Continue Reading
Control charts are a fantastic tool. These charts plot your process data to identify common cause and special cause variation. By identifying the different causes of variation, you can take action on your process without over-controlling it. Assessing the stability of a process can help you determine whether there is a problem and identify the source of the problem. Is the mean too high, too low,... Continue Reading
Last time I touched on the subject of the greatest Super Bowl quarterback, I promised a multivariate analysis considering several different statistics. Let’s get right to a factor analysis. Getting Ready for Factor Analysis One purpose of factor analysis is to identify underlying factors that you can’t measure directly. These factors explain the variation of many different variables in fewer... Continue Reading
Going into Saturday, Nebraska was 0-5 in games decided by 7 points or less and Michigan State was 4-0 in games decided by 7 points or less. You'll often hear sports analysts use this as proof that one team chokes under the pressure and the other team knows how to win in the clutch. But in reality, the result in close games can have just as much to do with luck as it can skill. Consider the formula... Continue Reading
Don't be a grumpy cat when something on your capability report doesn't smell right. After pressing that OK button to run your analysis, allow your inner cat to understand how and why certain statistics are being used. To help you along, here are some capability issues that customers have brought up recently. Cp is missing You’ve generated a capability analysis report with the Johnson transformation... Continue Reading
By Matthew Barsalou, guest blogger A problem must be understood before it can be properly addressed. A thorough understanding of the problem is critical when performing a root cause analysis (RCA) and an RCA is necessary if an organization wants to implement corrective actions that truly address the root cause of the problem. An RCA may also be necessary for process improvement projects; it is... Continue Reading
I have two young children, and I work full-time, so my adult TV time is about as rare as finding a Kardashian-free tabloid.  So I can’t commit to just any TV show. It better be a good one. I was therefore extremely excited when Netflix analyzed viewer data to find out at what point watchers get hooked on the first season of various shows. Specifically, they identified the episode at which 70% of... Continue Reading
4th and 1. It's a situation where the Big Ten 4th down calculator will never say to kick (unless, of course, it's the end of the game and a field goal will tie or take the lead). But what would it take to have the statistics suggest a punt? The key here is how far the punt travels. Last year the average Big Ten punt traveled about 40 yards. Using this value, in your own territory you'll score... Continue Reading
Easy access to the right tools makes any task easier. That simple idea has made the Swiss Army knife essential for adventurers: just one item in your pocket gives you instant access to dozens of tools when you need them.   If your current adventures include analyzing data, the Editor menu in Minitab 17 is just as essential. Whether you're organizing a data set, sifting through Session window output,... Continue Reading
Did you know that November is World Quality Month? The American Society for Quality is once again heading up this year’s festivities. Throughout the month of November, ASQ will be promoting the use of quality tools in businesses, communities, and institutions all over the world. You can check it out at http://asq.org/world-quality-month/. Here at Minitab, we’re also pretty excited about World... Continue Reading
I generally consider myself old-fashioned. I’m not particularly different on Halloween, where I dress up, pass out candy, sit down in front of the television to watch "It’s the Great Pumpkin, Charlie Brown" on ABC, and read Minitab blog posts from Halloweens past. But some younger folks have told me that I’m missing out, so I’m trying to broaden my horizons to include YouTube. I want to use data... Continue Reading
Since it's the Halloween season, I want to share how a classic horror film helped me get a handle on an extremely useful statistical distribution.  The film is based on John W. Campbell's classic novella "Who Goes There?", but I first became  familiar with it from John Carpenter's 1982 film The Thing.   In the film, researchers in the Antarctic encounter a predatory alien with a truly frightening... Continue Reading
As Halloween approaches, you are probably taking the necessary steps to protect yourself from the various ghosts, goblins, and witches that are prowling around. Monsters of all sorts are out to get you, unless they’re sufficiently bribed with candy offerings! I’m here to warn you about a ghoul that all statisticians and data scientists need to be aware of: phantom degrees of freedom. These phantoms... Continue Reading
Nebraska lost another close game, teams continue to incorrectly punt to Ohio State on 4th and short, and Northwestern keeps making terrible 4th down decisions. Another regular week for the Big Ten 4th down calculator. In case you haven't read the earlier entries in this series, I've used Minitab Statistical Software to create a model to determine the correct 4th down decision in Big Ten Conference... Continue Reading