The Lean Book of Lean

Appendix Glossary

In this appendix, I'm going to attempt to define a few of the common terms used in Lean and Six Sigma, both in the more professional way and, as par for this book, more everyday terms. If you're a well-versed practitioner of the art, please don't get too offended at the latter, it's really just a bit of fun! Not all the terms here are used or referenced in this book, but you might come across them as you move forward. Likewise, this is not an exhaustive list either.

^*Many thanks to isixsigma.com for some of the “Professional” Definitions

Term	“Professional” Definition*	“Common” Definition
5 Whys	The 5 Whys typically refer to the practice of asking five times why the failure has occurred in order to get to the root cause/causes of the problem. There can be more than one cause to a problem as well.	Being persistent and not accepting the first answer you get as the truth, the whole truth and nothing but the truth. Be careful this doesn't turn into interrogation!
5S	5S is a system for instilling order and cleanliness in the workplace. The Ss stand for: Seiri – Put things in order (Remove what is not needed and keep what is needed). Seiton – Proper arrangement (Place things in such a way that they can be easily reached whenever they are needed). Seiso – Clean (Keep things clean and polished; no trash or dirt in the workplace). Seiketsu – Purity (Maintain cleanliness after cleaning – perpetual cleaning). Shitsuke – Commitment (A typical teaching and attitude ...