My name is Meredith Griffith and I am a technical project manager at Minitab. I received a B.S. in Statistics from Virginia Tech and am finishing Penn State's M.S. program in Industrial Engineering with a focus on Quality Engineering. Having spent time in Quality Engineering and Marketing, I'm always looking for different ways to apply my knowledge of statistics and passion for quality improvement!
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
When I blogged about
automation back in March, I made my husband out to be an
automation guru. Well, he certainly is. But what you don’t know
about my husband is that while he loves to automate everything in
his life, sometimes he drops the ball. He’s human; even I have to
cut him a break every now and then.
On the other hand, instances of hypocrisy in his behavior tend
to make for a good story.... Continue Reading
Do you recall my “putting the cart before the horse” analogy in
part 1 of this blog series? The comparison is simple.
We all, at times, put the cart before the horse in relatively
innocuous ways, such as eating your dessert before you’ve eaten
your dinner, or deciding what to wear before you’ve been invited to
the party. But performing some tasks in the wrong order, such as
running a statistical... Continue Reading
first part of this series, we looked at a case study where
staff at a hospital used ATP swab tests to test 8 surfaces for
bacteria in 10 different hospital rooms across 5 departments. ATP
measurements below 400 units pass the swab test, while measurements
greater than or equal to 400 units fail the swab test and require
offered two tips on exploring and visualizing... Continue Reading
Working with healthcare-related data often feels different than
working with manufacturing data. After all, the common thread among
healthcare quality improvement professionals is the motivation to
preserve and improve the lives of patients. Whether collecting data
on the number of patient falls, patient length-of-stay, bed
unavailability, wait times, hospital acquired-infections, or
readmissions,... Continue Reading
Most of us have heard a backwards way of completing a task, or
doing something in the conventionally wrong order, described as
“putting the cart before the horse.” That’s because a horse pulling
a cart is much more efficient than a horse pushing a cart.
saying may be especially true in the world of statistics. Focusing
on a statistical tool or analysis before checking out the condition
of your... Continue Reading
After my husband’s most recent visit to the dentist, he returned
home cavity-free...and with a $150 electric toothbrush in
I wanted details.
It began innocently. His dreaded trip to the dentist ended in
high praise for no cavities and only a warning to floss more. That
prompted my programming-and-automation-obsessed husband, still in
the chair, to exclaim, "I wish there was a way to automate... Continue Reading
When I wrote
How to Calculate B10 Life with Statistical
Software, I promised a
follow-up blog post that would describe how to compute any “BX”
lifetime. In this post I’ll follow through on that promise, and in
a third blog post in this series, I will explain why BX life is one
of the best measures you can use in your reliability
As a refresher, B10 life refers to the time at which 10% of... Continue Reading
I was recently asked a couple of
questions about stability studies in Minitab.
Question 1: If you enter in a lower and upper spec in
the Stability Study dialog window, why do I see only one confidence
bound per fitted line on the resulting graph? Shouldn’t there be
You use a stability study to
analyze the stability of a product over time and to determine the
product's shelf life. In order to... Continue Reading
I recently guest lectured for an
applied regression analysis course at Penn State. Now, before you
begin making certain assumptions—because as any statistician will
tell you, assumptions are important in regression—you should know
that I have no teaching experience whatsoever, and I’m not much
older than the students I addressed.
I’m just 5 years removed from my undergraduate days at Virginia
Tech,... Continue Reading
Many of the things you need to
monitor can be measured in a concrete, objective way, such as an
item's weight or length. But, many important characteristics are
more subjective, such as the collaborative culture of the
workplace, or an individual's political outlook.
A survey is an excellent way to measure these kinds of
characteristics. To better understand a characteristic, a
researcher asks... Continue Reading
To choose the
right statistical analysis, you need to know the distribution of
your data. Suppose you want to assess the capability of your
process. If you conduct an analysis that assumes the data follow a
normal distribution when, in fact, the data are nonnormal, your
results will be inaccurate. To avoid this costly error, you must
determine the distribution of your data.
So, how do you determine... Continue Reading
Over the last year or so I’ve
heard a lot of people asking, “How can I calculate B10 life in
Minitab?” Despite being a statistician and industrial engineer
(mind you, one who has never been in the
field like the customers asking this question) and having taken a
reliability engineering course, I’d never heard of B10 life. So I
did some research.
The B10 life metric originated in the ball and roller... 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,
Pennsylvania, with subsidiaries in the United Kingdom, France, and
Australia. Our global network of representatives serves more than 40
countries around the world.