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Inderjit Arora
Objective auditing has always been a challenge, and this is especially true now for ISO 9001:2015 audits. To better meet customer expectations, fundamental changes have been introduced to the standard to address current business realities and advancements in technology. Much of the responsibility…
Greg Fox
Mind the gap. It’s is an important concept to bear in mind when traveling on the Tube in London, the T in Boston, the Metro in Washington, D.C., and other subways. But how many of us remember to mind the gap when we create an interval plot in Minitab Statistical Software? Not too many of us, I’d…
NIST
NIST scientists have devised and improved a prototype instrument the size of a loaf of bread that can substantially increase the accuracy of length measurements in commerce. Perhaps surprisingly, it does so by achieving the most accurate measure of the refractive index of air reported to date.
An…
Donald J. Wheeler
Here we look at a simple example to discover the commonalties of various data analysis techniques widely used in industry today. Careful consideration of the following may result in insights that were not part of your introductory class in statistics.
Our example uses the gate oxide thicknesses…
Diane Lee
Like many of you, I venture out on Saturday mornings to get groceries and gas. Until my college years, I never thought much about whether or not I paid the right amount at the pump, if the supermarket scale was correct, or if packaged foods actually contained the amount of product stated on the…
Joel Smith
For the majority of my career with Minitab, I’ve had the opportunity to speak somewhat regularly at conferences and other events. I thought some of my talks were pretty good, and some were not so good (based on ratings, audiences didn't always agree with my opinion at either extreme—but that's a…
Eston Martz
If you want to convince someone that at least a basic understanding of statistics is an essential life skill, bring up the case of Lucia de Berk. Hers is a story that’s too awful to be true—except that it’s completely true.
A flawed analysis irrevocably altered de Berk’s life and kept her behind…
TÜV SÜD America
The revised ISO 9001:2015 standard was published on Sept. 23, 2015. The release of this standard has many organizations preparing for the transition from ISO 9001:2008, and with transition comes uncertainty: How long will it take? What will it cost my organization? Where do I start? These and…
Dan Nelson
Have you ever noticed someone struggling with a problem because he didn’t know the “trick” to solving it? Have you ever wrestled with a problem, only to discover that it actually wasn’t a problem; you were simply approaching it improperly? In these cases, the way forward is usually apparent after…
Arun Hariharan
Technology is a useful tool in quality. That said, there are limits to what technology can do. Here’s my summary of its advantages and disadvantages for quality professionals.
1. Data and measurements. Technology can help you automate measurements and analysis of data (Minitab statistical software…
Donald J. Wheeler
The Levey-Jennings chart was created in the 1950s to answer questions about the quality and consistency of measurement systems in the chemical and process industries. This column will illustrate the fatal flaw in this technique and show a better way to track the consistency of your measurement…
Greg Fox
Unless you live under a rock, you’ve no doubt heard that the world recently lost David Bowie, one of the greatest artists of our time. My memories of the Thin White Duke go all the way back to my formative years. I recall his music echoing through the halls of our house as I crooned along while…
Eston Martz
Not long ago, I couldn’t abide statistics. I respected the field, in much the same way a gazelle respects a lion. Most of my early experiences with statistics indicated that close encounters resulted in pain, so I avoided further contact whenever possible.
So how is it that today I write about…
Donald J. Wheeler
One computation that modern software offers to unsuspecting users is the statistical tolerance interval. Since this sounds very much like limits for individual values, some have been tempted to use them on process behavior charts in place of the traditional three-sigma limits for individual values…
Fred Schenkelberg
The planning of environmental or reliability testing becomes a question of sample size at some point. It’s probably the most common question I hear as a reliability engineer: How many samples do we need?
Also, when evaluating supplier-run test results, we need to understand the implications of…
Davis Balestracci
“It is impossible to tell how widespread data torturing is. Like other forms of torture, it leaves no incriminating marks when done skillfully. And like other forms of torture, it may be difficult to prove even when there is incriminating evidence.” —J. L. Mills
When will academics, Six Sigma…
William A. Levinson
The Shewhart control chart is relatively insensitive to non-normal distributions, and the worst foreseeable consequences of a wrong decision involve searching for an assignable or special cause when none is present. The economic consequences depend on the time wasted, and whether unnecessary…
Michelle Paret
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…
Davis Balestracci
“When I die, let it be in a meeting. The transition from life to death will be barely perceptible.” —Anonymous
Today I’m going to share some ideas from an always-thoughtful newsletter written by Steve Harden of LifeWings—a company of pilots who use aviation ideas to create cultures of safety in…
Douglas C. Fair
Sponsored Content
Statistical process control (SPC) software has been around for decades, used by manufacturers across industries to help monitor process behavior and control quality on the shop floor. Like any technology, the software has evolved over the years into something much more than a…
Eston Martz
I read trade publications that cover everything from banking to biotech, looking for interesting perspectives on data analysis and statistics, especially where they pertain to quality improvement.
Recently I read a great blog post by Tony Taylor, an analytical chemist with a background in…
William A. Levinson
We all know what happens when we assume. For example, traditional designed experiments assume that residuals, the differences between the actual and modeled data, follow the normal distribution (as seen in figure 1). These experiments include t tests, analysis of variance (ANOVA), factorial…
Jim Colton
How many samples do you need to be 95-percent confident that at least 95 percent—or even 99 percent—of your product is good? The answer depends on the type of response variable you are using—categorical or continuous.
The type of response will dictate whether you’ll use: 1. Attribute sampling:…
Eston Martz
Whatever industry you’re in, you’re going to need to buy supplies. If you’re a printer, you’ll need to purchase inks, various types of printing equipment, and paper. If you’re in manufacturing, you’ll need to obtain parts that you don’t make yourself. But how do you know you’re making the right…
Scott A. Hindle
When considering how good a production process is, it’s important to ask, “Can we expect the output to be fully conforming?” An assessment of process capability can answer this. Data are needed, but how many? Is “30” the right number? This article examines these last two questions.
First, why 30…