Improvement Insights Blog
You Don’t Need to Know Statistics to Do Statistical Process Control (SPC)
People think you have to know statistics to do Statistical Process Control (SPC). Not true, here’s why.
“I’ve noticed that whenever I say the phrase “Statistical Process Control,” people start to freak out. It’s unnecessary because guess what? You don’t need to know statistics to do Statistical Process Control.
“Shewhart was a statistician, he figured out how to calculate the variances and… how to calculate the upper and lower control limits and what that all means. Then Nelson expanded all of that stuff, so the statisticians did the statistical part. Your software (like QI Macros) will do all those calculations for you, and whether you’re using QI Macros or anything else, we all use the same formula so you don’t have to worry about that. All right?
“So this is the secret sauce. What do you have to know? Well, if you have too much variation, we want to reduce the variation; that’s classic Six Sigma talk, right? So if we have a control chart, what we want to do is reduce the variation. The other thing you can do is you can increase the center line or lower the center line. So if we want to reduce defects, we want the center line to move down. If we want to increase patient satisfaction we want to move [the center line] up, right? Or if we want to make our pistons harder we want them to be more, dense more [resistant] to wear and tear. Does this make sense? So that’s it: reduce variation, move the center line up or down.
“You don’t need to know statistics to do Statistical Process Control, you just need software that does it for you, I’m telling you what: you’re not going to do this by hand; it takes too long, costs too much. Isn’t there an app for that? Yes, there is: QI Macros.
“So that’s my Improvement Insight for this week. Let’s create a hassle-free America; hassle-free healthcare. Let’s start using the tools of Quality: control charts to sustain or simplify or optimize whatever it is we need to. Let’s go out and improve something this week.”