This is a clearly written book that presents Taguchi's ideas on quality control. Explained nicely is the loss function of Taguchi that has become so popular. Also, discussed in detail are models for online quality control, tolerancing, and preventive maintenance. (This book is not about Taguchi's celebrated work on design of experiments.) Although some theory appears to be heuristically derived, what needs to be pointed out here is that some of these methods have been used in Toyota! So there is a clear value to reading about them. One would think this would be mandatory reading for a graduate course on quality control, but instead the book has gone out of print! When I was a graduate student, I was really lucky to have a professor who used this book as a text book.