Have you ever met people who “do” statistical process control (SPC) only to get some screwy-looking control chart, and then text: OMG I H8 SPC! (If you don’t understand that, ask your nine-year-old child or grandchild.)

Last month we saw how it is not a failure of SPC, but rather an EBKAC (error between keyboard and chair). As I wrote in my last article, “Why Doesn't SPC Work?” perhaps they are not doing the measurement system analysis first, or perhaps autocorrelation in a continuous process. But you batch process folks are not off the hook, which is what this month’s article is about.

One of the most useful diagnostic tools for understanding what is going on in a process is the statistical process control chart (SPC). This is also a frequently misunderstood tool, and these misunderstandings lead to misdirected effort during a Six Sigma process, resulting in lost time and money. All the questions related to these foiled efforts boil down to this, “I used my software to make a control chart, but the chart looks all messed up. Why doesn’t SPC work?”

It does, if you avoid some common pitfalls. So today, I am kicking off a few articles about these pitfalls that I hope will make your projects less frustrating and more efficient.