For full disclosure, I spent a few years as a practicing six sigma black belt for a top six sigma corporation, so my review is certainly biased. I'm comparing this small inexpensive book to six weeks of training, several years of practicing, and a stack of training materials measuring 30 inches deep.
This book compares very, very well to that training in most regards. I docked it a star because there are a few gaps that I think are huge misses, but I could easily see this book with 5 stars.
Key things I liked about the book:
+ Many, many six sigma tools are explained very well, especially my favorites: the Failure Modes Effects Analysis (FMEA) and control charts. I didn't find anything wrong about the explanations, and in fact, identified the key points I would highlight to a student (e.g. caution about how Detection scoring flips on you for the FMEA).
+ There's a nice introduction into Lean, which is truly a close cousin to six sigma. No six sigma instruction should be without it. (My employer treated it as part of six sigma.)
+ When I saw the quote "in God we trust, all others bring data" I knew these guys were experienced practitioners.
+ Explanation not only of the statistical equations, but more importantly, the statistical tools you need to consider getting. Because NO ONE is hand-calculating this stuff people! You need the tools to play around with the data, see how it works, identify errors, etc.
What didn't I like?
- No discussion of Design for Six Sigma, DESPITE a brief mention of it! Again, my previous employer saw DFSS as part of six sigma, and learning it (like Lean) is required for a black belt. They should have included a short intro to it like they did for Lean.
- This book desperately needs a chapter on why projects fail. This is extremely critical. Most people think six sigma is all about the math. It IS NOT. The math is truly the easiest part. The hard part is completing the project. Time and again I saw projects fail for a handful of reasons. The authors touch on many of the causes, but without calling them out specifically, they are dooming novice practitioners to fail. Most people think it's about doing the right stats but a lot of it is finding the right champion and getting him/her to support your work through to the end.
- The authors need to call out that tools like Minitab and JMP are not something that anyone could pick up and start using. They require real training. If you want to use these tools, budget for classes. You need them. Also, SigmaXL (a plug-in for Excel that does six sigma calculations) is a buggy piece of dog doo. I have it installed now because my current employer is too cheap to buy us all JMP or Minitab. SigmaXL, well, you get what you pay for. It can do the math, but the journey will be a rough one where you will remember curse words you haven't heard in years.
I hope those who pick this book up are excited about what six sigma can do for their company. But it really isn't the key to success. It's a methodology, and many will work. There are no silver bullets or free lunches. Before picking up this book, consider if your company is ready to examine how it does business with no sacred cows. Make sure you have a strong champion at the very top who will provide air cover when you start asking very uncomfortable questions. Make sure the team buys in to the methodology and will continue to run with it after you hand the work over to the process owners. Most projects fail, and there's nothing special about six sigma that excuses it from that grim fate.