All Features
Donald J. Wheeler
The question “Is this batch like the others?” is asked all over the world on a daily basis. It turns out that the process behavior chart provides a very effective answer for questions about the homogeneity of the product stream.
In World War II, Gen. Leslie Simon used the process behavior chart…
Scott A. Hindle
A t the end of part three of this four-part series on process capability, Alan was ready to identify a contact at the factory who could assist in providing some context around the collected data and the overall production process.
Discussion with Joe
Joe, working on the production team, was the…
Scott A. Hindle
Part two of this four-part series on process capability concluded with Alan just about to meet Sarah for a second time. He thought he was making good progress with his analysis of Product 874 data until he was asked to assess process capability, even though it can’t be assessed for an unstable…
Scott A. Hindle
In part one of this four-part series, we considered the basics of process capability, as witnessed through the learning curve of Alan in his quest to determine the product characteristics of the powder, Product 874. We pick up with Alan here as he prepares for his second meeting with his colleague…
Scott A. Hindle
In my August 2015 article, “Process Capability: How Many Data?” I discussed whether 30 data were the “right” number in an analysis of process capability. In this four-part series, the focus is on understanding what process capability is and the pitfalls associated with it, along with how it can…
Davis Balestracci
I hope this little diversion into design of experiments (DOE) that I’ve explored in my last few columns has helped clarify some things that may have been confusing. Even if you don’t use DOE, there are still some good lessons about understanding the ever-present, insidious, lurking cloud of…
Meredith Griffith
When I wrote about automation back in March, I made my husband out to be an automation guru. He certainly is, but what you don’t know about my husband is that, although he loves to automate everything in his life, sometimes he drops the ball. He’s human. On the other hand, instances of hypocrisy…
Fred Schenkelberg
Spending too much on reliability and not getting the results you expect? Just getting started and not sure where to focus your reliability program? Or, just looking for ways to improve your program?
There’s not one way to build an effective reliability program. The variations in industries,…
Donald J. Wheeler
Having described the report card chart and the process monitor chart in previous columns, we now turn to a third way that people use process behavior charts—the process trial chart. Here the emphasis shifts from the detection of unknown changes or upsets to the evaluation of deliberate changes…
Patrick Runkel
It’s been called a “demographic watershed.” During the next 15 years alone, the worldwide population of individuals aged 65 and older is projected to increase more than 60 percent, from 617 million to about 1 billion, according to a U.S. Census Bureau report.
Increasingly, countries are asking…
Donald J. Wheeler
Story update 10/9/2023: This article is a corrected version. The earlier version suffered from a programming error that affected all of the PID results.
Many articles and some textbooks describe process behavior charts as a manual technique for keeping a process on target. For example, in Norway…
Gillian Groom
You often hear the data being blamed when an analysis does not deliver the expected answers. I was recently reminded that the data chosen or collected for a specific analysis is determined by the analyst, so there is no such thing as bad data—only bad analysis.
This made me think about the steps…
Bruno Scibilia
Businesses are getting more and more data from existing and potential customers. Whenever we click on a website, for example, it can be recorded in the vendor’s database, and whenever we use electronic ID cards to access public transportation or other services, our movements across the city may be…
Barbara A. Cleary
Approaching the end of the school year means focusing on graduation rates, dropout rates, and other data suggesting trends for students. Opportunities for considering statistics abound, but one must examine the way that these statistics are actually used by asking the right questions about the…
Ken Levine
How do you determine the “worst case” scenario for a process? Is it by assuming the worst case for each process task or step? No. The reason is that the probability of every step having its worst case at the same time is practically zero. What we’re looking for is a value that will occur a very…
Ken Voytek
In a recent post, I examined the differences in productivity across small and large manufacturing firms, and noted that there were differences across manufacturers in terms of size. But it’s also clear from the literature that productivity differs across companies even in the same industry.
Why…
Greg Fox
Remember the classic science fiction film The Matrix? The dark sunglasses, the leather, computer monitors constantly raining streams of integers (inexplicably in base 10 rather than binary or hexadecimal)? And that mind-blowing plot twist when Neo takes the red pill from Morpheus’ outstretched…
Patrick Runkel
What does the eyesight of a homeless person have in common with complications from dental anesthesia? Or with reducing side-effects from cancer? Or monitoring artificial hip implants?
These are all subjects of recently published studies that use statistical analyses in Minitab to improve…
Davis Balestracci
In my last column I explained how many situations have an inherent response surface, which is the “truth.” However, any experimental result represents this true response, which is unfortunately obscured by the process’s common-cause variation. Regardless of whether you are at a low state of…
Donald J. Wheeler
The simple process behavior chart can be used in many different ways. Since report card data are common in all types of businesses, the report card chart is often the first chart that people create. Some of the pros and cons of report card charts are covered here.
Report card data are data that…
Patrick Runkel
The Pareto chart is a graphic representation of the 80/20 rule, also known as the Pareto principle. If you’re a quality improvement specialist, you know that the chart is named after the early 20th-century economist Vilfredo Pareto, who discovered that roughly 20 percent of the population in Italy…
Davis Balestracci
I’ve mentioned that design of experiments (DOE) is one of the few things worth salvaging from typical statistical training, and I thought I’d talk a bit more about DOE in the next couple of columns. The needed discipline for a good design is similar when using rapid-cycle plan-do-study-act (PDSA…
Brooke Pierce
The healthcare industry is in a state of constant change, and with change comes opportunity. With the passage of the Affordable Care Act (ACA) and the Medicare Access and CHIP Reauthorization Act (MACRA), healthcare providers are, or will be, paid differently for their services. No longer can they…
Donald J. Wheeler
Experimental designs that result in orthogonal data structures allow us to get the most out of both our analysis and our research budget. As a result, designed experiments have been used for everything from basic research to process optimization. These multiple roles make it crucial to understand…
Donald S. Holmes, A. Erhan Mergen
Regression analysis is used in a variety of manufacturing applications. An example of such an application would be to learn the effect of process variables on output quality variables. This allows the process control people to monitor those key variables and keep the output variables at the…
