Screening experimental designs allow you to study a very large
number of factors in a very limited number of runs. The objective
is to focus on the few factors that have a real effect and
eliminate the effects that are not significant. This is often the
initial typical objective of any experimenter when a
DOE (design of experiments) is performed.
Table of Factorial Designs
Consider the table below.... Continue Reading
NOTE: This story will reveal how easy it can
be to optimize settings using the statistical method called Design
of Experiments, but it won't provide easy answers for making your
own office coffee any better.
her team’s ultimatum about the wretched office coffee, Jill used
the design-of-experiments (DOE) tool in Minitab 17’s Assistant to
design and analyze a screening study. Jill now knew... Continue Reading
loves a Pareto chart. That is, everyone who knows that
Pareto charts are a type of bar chart ordered by bar size to help
you to determine which bars comprise the vital few that you care
about and which are the trivial many that you don't care about.
Pareto charts are a great tool for communicating where the largest
gains can be made as you focus your improvement efforts.
Since I love... Continue Reading
Blind Wine Part I, we introduced our experimental setup, which
included some survey questions asked ahead of time of each
participant. The four questions asked were:
On a scale of 1 to 10, how would you rate your knowledge of
How much would you typically spend on a bottle of wine in a
How many different types of wine (merlot, riesling, cabernet,
etc.) would you buy regularly (not as... Continue Reading
Already relaxed on his first day in Napa, Brutus and his wife
Suzy decide to visit their favorite winery just before lunch to
taste their new Cabernet Sauvignon. The owner recognizes them as
they walk in the door and immediately seats them on the patio
overlooking the vineyard. Two glasses appear, and as the owner
tells them about the new Cabernet, Brutus prepares for an onslaught
of blackberry... Continue Reading
common to think that process improvement initiatives are meant to
cater only to manufacturing processes, simply because manufacturing
is where Lean and Six Sigma began. However, many other industries,
in particular financial services and banking, also rely on data
analysis and Lean Six Sigma tools to improve processes.
Rod Toro is a business process improvement manager at Edward
Jones, and I... Continue Reading
2014 ASQ World
Conference on Quality and Improvement is coming up in early May
in Dallas, and this year’s International Team Excellence Award
Process (ITEA) will also come to a close at the conference, as
winners from the finalist teams will be chosen for ASQ gold,
silver, or bronze-level statuses.
The annual ASQ ITEA process celebrates the accomplishments of
quality improvement... Continue Reading
If you’ve been looking at Minitab 17, you’ve noticed a lot of
new enhancements. For me, the biggest of these is the addition of
Design of Experiments (DOE) to
the Assistant. DOE in the Assistant has so many exciting
aspects it’s hard to take it all in at once, but here are 5
highlights for when you plan and create a screening experiment:
1. Just-in-time guidance
If you’re lucky, you’ve had the... Continue Reading
factors significantly affect how quickly my couch-potato pooch
obeys the “Lay Down” command?
The cushiness of the floor surface? The tone of voice used? The
type of reward she gets? How hungry she is?
I created a 1/8 fraction Resolution IV design
for 7 factors and collected response data for 16 runs. Now it’s
time to analyze the data in Minitab, using Stat
> DOE > Factorial > Analyze Factorial... Continue Reading
Nala, our 6-year-old
golden retriever, loves her dogma. That's her sitting
in front of church on Sunday morning.
But she's not crazy about her catechism. For example, she
doesn't always dutifully follow the "Lay Down" commandment.
What factors may be influencing her response? We're
performing a DOE screening experiment to find out.
In this post, we'll use Minitab
Statistical Software to
Create the... Continue Reading
of experiments (DOE) is an extremely practical and cost-effective
way to study the effects of different factors and their
interactions on a response.
But finding your way through DOE-land can be daunting when
you're just getting started. So I've enlisted the support of a
friendly golden retriever as a guide dog to walk us through a
simple DOE screening experiment.
Nala, the golden retriever,... Continue Reading
a customer called our Technical Support team about a Design of Experiment he
was performing in Minitab Statistical Software. After they helped
to answer his question, the researcher pointed our team to an
interesting DOE he and his colleagues conducted that involved using
nasal casts to predict the drug delivery of nasal spray.
The study has already been published, and you can read... Continue Reading
processes are affected by various
sources of variations over time. Products which are designed
based on optimal settings, will, in reality, tend to drift away
from their ideal settings during the manufacturing process.
Environmental fluctuations and process variability often cause
major quality problems. Focusing only on costs and performances is
not enough. Sensitivity to deterioration and... Continue Reading
2013 ASQ World Conference is taking place this week in
Indianapolis, Indiana, and it's been a treat to see how our
software was used in the projects highlighted in many of the
presentations. As a supporter of the conference, a key event for
quality practitioners around the world, Minitab was proud to
sponsor one of the presentations that seemed to get a lot of
attendees talking. Scott... Continue Reading
know the drill…you’re in Six Sigma training and you’re learning how
to conduct a design of experiment (DOE). Everything is making
sense, and you’ve started thinking about how you’ll apply what you
are learning to find the optimal settings of a machine on the
factory floor. You’ve even got the DOE setup chosen and you know
the factors you want to test …
Then … BAM! … You’re on your own and you... Continue Reading
When I talk to quality professionals about how they use
statistics, one tool they mention again and again is design of
experiments, or DOE. I'd never even heard the term before I started
getting involved in quality improvement efforts, but now that I've
learned how it works, I wonder why I didn't learn about it sooner.
If you need to find out how several factors are affecting a process
outcome,... Continue Reading
Six Sigma and process excellence leaders are often asked to “remove
defects” from products and processes. This can be quite a
challenge! Lou Johnson, senior Minitab technical trainer and
mentor, has some tips that might help if you’re faced with this
situation. I had the chance to talk with Lou, and here’s what he
shared with me about how to first approach a DOE.
How to Approach a DOE
Before... Continue Reading
the most wonderful time of the year – the time for holiday bakers
and cookie monsters to unite! So what’s a quality improvement
professional to do when his favorite sugar cookie recipe produced
cookies that failed to hold their festive holiday shapes after
being baked? Run a Design of Experiment (DOE), of course!
A Fractional Factorial Experiment
Bill Howell, an avid baker and... Continue Reading
of experiments, experimental design, or just "gathering some data."
Whatever you want to call it, your approach to doing it will affect
the results you get.
Have you ever wondered about all those contradictory studies in
the news, especially regarding what's good and bad for you? Coffee
is good for you, one headline says. It's bad for you, says the
next. And if you read beyond the headlines,... Continue Reading
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