When I get to apply tools like the P’ Chart, I get a thrill.
What can I say? I’m a huge fan of Minitab® Statistical
Software. I won’t claim to be its biggest fan, but let’s just
say I’m definitely up there. Probably in the top 50;
definitely the top 100.
Admittedly, I’m biased. I have a pretty good gig here. But
my history with Minitab started more than a decade before I came to
work here. As a... Continue Reading
we’ve explored using gummi bears to do a gage Linearity and Bias
Study and a Type I Gage Study, it’s time to use gummi bears to
practice the third and final type of measurement systems analysis
that I’m planning to demonstrate: the gage R&R study."R&R" stands for Repeatability and Reproducibility, which are
the two sources of variation we typically evaluate in a gage
R&R study.... Continue Reading
You know that song "Once in a Lifetime," by Talking Heads?
The one where David Byrne keeps repeating "Same as it ever
"Same as it never was" is more like it. We
confront variation constantly.
Think about it. Did you spend exactly the same amount of time
commuting to work today as you did yesterday? No? That's variation.
While these planes look identical, some variation exists. But... Continue Reading
In my post Assessing Variability for Quality Improvement,
I showed how measuring variability is as important as measuring the
mean for a product or service in a quality improvement initiative.
The mean, by itself, often tells an incomplete story. Additionally,
quality management veterans know that controlling the variability
is often more difficult than controlling the mean. If you want to
change... Continue Reading
It looks like I
may have gotten my wish:
NBA games should start Christmas day, which will be a huge present
to a lot of fans. So while I ponder whether to proceed with a
second post about statistics related to the lockout, let's shed
some light on a different subject. From time to time, Minitab users will call in needing assistance
with control charts. One common problem people encounter... Continue Reading
Manufacturers need to make items that meet a customer’s
standards, or they’ll soon be out of business. That’s why quality
engineers devote a good deal of time to making sure that processes
are able to meet those standards.
The first step is to make sure your process is stable. After
all, you can’t predict the performance of an unstable process. But
you can predict and improve on a stable process.
I... Continue Reading
Did you know that November is World Quality Month?
The American Society for Quality (ASQ) started the annual event
last year to celebrate quality and its impact in the world.
Throughout the month of November, ASQ will be showcasing the
advancements and valuable quality contributions in businesses,
communities, and institutions throughout the world.How are we celebrating at Minitab?-Adding new... Continue Reading
we’re going to get ready to do a Gage Linearity and Bias Study with
gummi bears. But to do the linearity and bias study, you first have
to talk more about how to collect the data. The Gage Linearity and
Bias study has a complication that wasn’t present in the Type 1 Gage Study.The point of the gage linearity and bias study is to assess the
bias of a gage across its operating range, not just... Continue Reading
We often see an average (a.k.a. the mean) used to summarize a
population or a process. For example, a pizza restaurant might
state that their mean delivery time is 20 minutes. Deceptively,
this seems like a very intuitive measure.While the mean is important, people often react to the variability
even more. Variability is a measure of how spread out the data are
from the mean. How many times have... Continue Reading
Multivariate statistics can be used to better understand the
structure of large data sets, typically customer-related data.
Suppose you have a large amount of data about your customers
(preferences, degree of satisfaction, expectations,
dislikes etc…), and a large number of variables you need to
Your data might seem somewhat chaotic at first, and you might
consider the use of many different...Continue Reading
Gummi bears have
more to teach us about
measurement systems analysis.Today, we’ll look at doing a Type 1 Gage Study, which compares the
measurement variation to the specifications for your process, to
judge whether a gage is measuring well enough. The Type 1 Gage
Study is a starting point because it evaluates accuracy, precision,
and consistency, but only for a single case. Later, we’ll look... Continue Reading
What can gummi bears tell us about measurement system
We're still practicing statistics with gummi
bears, because they don't bounce or slide off of popsicle
sticks. In my last post, we looked at some factors that might
affect how far a gummi bear flies off of a popsicle stick catapult.
Next, what we'd really like to do is to pick some factors to study
and do a designed experiment to... Continue Reading
When you're conducting a Capability Analysis, do you know which
statistic to look at? We get a fair number of questions about
this, so let's explore the question.
In the graph below, you’ll see that there are two categories for
Capability Statistics, Potential and Overall:
The Potential (Within) Capability statistics(Cp, CPL…) are based
off of the estimate for within standard deviation. Well,... Continue Reading
So I’m standing at my desk last Tuesday, when my legs suddenly
turn to Jell-O. Then I notice the overhead lights gently waving.
Soon folks are popping out of their offices with quizzical,
sometimes queasy expressions. A few phone calls and Internet
searches confirm that we have just experienced a very rare, East
Coast earthquake. One centered in Virginia but felt from Georgia to
Maine. Wow.We were... Continue Reading
I’ve had the opportunity to talk to several quality
improvement professionals from companies across many different
industries, and I’ve heard about the common challenges
practitioners face when they’re completing quality improvement
projects. Here's a brief summary:Where do I start?A challenge faced by quality practitioners, especially newer Green
Belts, is the breadth of available quality tools... Continue Reading
Recently I've been thinking about common questions that
customers ask when running a Gage R&R analysis in Minitab.
For example, when you run a Gage R&R, the last result that
shows up in the session window is a value for the ‘Number of
Distinct Categories’. This one metric is something that
customers seem to overlook when they call to discuss their Gage
This value represents the... Continue Reading
They say "variety is the spice of life," but when it comes to
doing business, variation is not your friend. That's why we have
One of these things is not like the others...is
it common cause variation you can accept, or special variation that
needs to be addressed? Control charts could tell you.
We know that a little bit of variation is inevitable, but we
tolerate it within... Continue Reading
I was 'lucky' enough to learn about how Betfair, one
of the world's largest online sports betting communities, employs
quality improvement in their day-to-day business. Here's a snippet
of the case
Betfair turned to Minitab when a crucial process for helping new
customers get started needed improvement.
The company invests heavily in different marketing activities,
including an outbound... Continue Reading
I was reading an article recently about Jackson Pollock, an
abstract artist famous for his “drip paintings,” and I became
intrigued when I found out his art falls under the category of
“process art.” As I learned more about Pollock and his “process,” I
started to think about what he could teach us about process
improvement.The process Pollock took to make his artwork was very calculated,
hence the... Continue Reading
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