by Matthew Barsalou, guest blogger
At the end of
the first part of this story, a group of evil trouble-making
chickens had convinced all of their fellow chickens to march
on the walled city of Wetzlar, where, said the evil chickens, they
all would be much happier than they were on the farm. The chickens marched through the night and arrived at Wetzlar on
the Lahn as the sun came up. “Let us in!”... Continue Reading
The Six Sigma quality improvement methodology has lasted for
decades because it gets results. Companies in every country around
the world, and in every industry, have used this logical,
step-by-step method to improve the quality of their processes,
products, and services. And they've saved billions of dollars along
However, Six Sigma involves a good deal of statistics and data
analysis,... Continue Reading
Six Sigma is a quality improvement method that businesses have
used for decades—because it gets results. A Six Sigma project
follows a clearly defined series of steps, and companies in every
industry in every country around the world have used this method to
resolve problems. Along the way, they've saved billions of
But Six Sigma relies heavily on statistics and data analysis,
and many... Continue Reading
Can you trust your data?
the very first question we need to ask when we perform a
statistical analysis. If the data's no good, it doesn't matter what
statistical methods we employ, nor how much expertise we have in
analyzing data. If we start with bad data, we'll end up with
unreliable results. Garbage in, garbage out, as they
So, can you trust your data? Are you positive?... Continue Reading
Have you ever had a probability
plot that looks like this?
The probability plot above is based on patient weight (in
pounds) after surgery minus patient weight (again, in pounds)
The red line appears to go through the data, indicating a
good fit to the Normal, but there are clusters of plotting
points at the same measured value. This occurs on a probability
plot when there are many... Continue Reading
Last week I was fielding questions on social media about Minitab
18, the latest version of our statistical software. Almost as soon
as the new release was announced, we received a question that comes
up often from people in pharmaceutical and medical device
Minitab 18 FDA-validated?"
How Software Gets Validated
That's a great question. To satisfy U.S. Food and Drug
Administration (FDA)... Continue Reading
by Dan Wolfe, guest blogger
How would you measure a hole that was allowed to vary one tenth
the size of a human hair? What if the warmth from holding the part
in your hand could take the measurement from good to bad? These are
the types of problems that must be dealt with when measuring at the
As a Six Sigma professional, that was the challenge I was given
when Tenneco entered into... Continue Reading
charts are excellent tools for looking at data points that seem
unusual and for deciding whether they're worthy of investigation.
If you use control charts frequently, then you're used to the idea
that if certain subgroups reflect temporary abnormalities, you can
leave them out when you calculate your center line and control
limits. If you include points that you already know are... Continue Reading
Before cutting an expensive piece of granite for a countertop, a
good carpenter will first confirm he has measured correctly. Acting
on faulty measurements could be costly.
no measurement system is perfect, we rely on such systems to
quantify data that help us control quality and monitor changes in
critical processes. So, how do you know whether the changes you see
are valid and not just the... Continue Reading
For the majority of my career, I've
had the opportunity to speak at conferences and other events
somewhat regularly. I thought some of my talks were pretty good,
and some were not so good (based on ratings, my audiences didn't
always agree with either—but that's a topic for another post). But
I would guess that well over 90% of the time, my proposals were
accepted to be presented at the... Continue Reading
Users often contact Minitab technical support to ask how the
software calculates the control limits on control charts.
A frequently asked question is how the control limits are
calculated on an
I-MR Chart or Individuals Chart. If Minitab plots the upper and
lower control limits (UCL and LCL) three standard deviations above
and below the mean, why are the limits plotted at values other than
3 times... Continue Reading
One of the most memorable presentations at the inaugural Minitab
Insights conference reminded me that data analysis and quality
improvement methods aren't only useful in our work and businesses:
they can make our home life better, too.
presenter, a continuous improvement training program manager at an
aviation company in the midwestern United States, told attendees
how he used Minitab... Continue Reading
One highlight of writing for and editing the Minitab Blog is the
opportunity to read your responses and answer your questions.
Sometimes, to my chagrin, you point out that we've made a mistake.
However, I'm particularly grateful for those comments, because it
permits us to correct inadvertent errors.
feared I had an opportunity to fix just such an error when I saw
this comment appear on one of... Continue Reading
"Data! Data! Data! I can't make bricks without clay."
— Sherlock Holmes, in Arthur Conan Doyle's The Adventure
of the Copper Beeches
Whether you're the world's greatest detective trying to crack a
case or a person trying to solve a problem at work, you're going to
need information. Facts. Data, as Sherlock Holmes
But not all data is created equal, especially if you plan to
analyze as part of... 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 Companion by Minitab.
Companion by Minitab is a software platform that... Continue Reading
shopping. For some, it's the most dreaded household activity. For
others, it's fun, or perhaps just a “necessary evil.”
Personally, I enjoy it! My co-worker, Ginger, a content manager
here at Minitab, opened my eyes to something that made me love
grocery shopping even more: she shared the data behind her family’s
shopping trips. Being something of a data nerd, I really geeked out
over the... Continue Reading
you regularly perform regression analysis, you know that
R2 is a statistic used to evaluate the fit of your
model. You may even know the standard definition of R2:
the percentage of variation in the response that is explained
by the model.
Fair enough. With Minitab Statistical Software doing all the heavy
lifting to calculate your R2 values, that may be all you
ever need to know.
But if you’re... Continue Reading
Everyone who analyzes data regularly has the experience of
getting a worksheet that just isn't ready to use. Previously I
wrote about tools you can use to
clean up and eliminate clutter in your data and
reorganize your data.
In this post, I'm going to
highlight tools that help you get the most out of messy data by
altering its characteristics.
Know Your Options
Many problems with data don't become... Continue Reading
In Part 1 of this blog series, I
compared Six Sigma to a diamond because both are valuable, have
many facets and have withstood the test of time. I also explained
how the term “Six Sigma” can be used to summarize a variety of
concepts, including philosophy, tools, methodology, or metrics. In
this post, I’ll explain short/long-term variation and
between/within-subgroup variation and how they help... Continue Reading
You've collected a bunch of
data. It wasn't easy, but you did it. Yep, there it is, right
there...just look at all those numbers, right there in neat columns
and rows. Congratulations.
I hate to ask...but what are you
going to do with your data?
If you're not sure precisely
what to do with the data you've got, graphing it is a
great way to get some valuable insight and direction. And a good
graph to... Continue Reading
Minitab is the leading provider of software and services for quality
improvement and statistics education. More than 90% of Fortune 100 companies
use Minitab Statistical Software, our flagship product, and more students
worldwide have used Minitab to learn statistics than any other package.
Minitab Inc. is a privately owned company headquartered in State College,
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