This handbook is a helpful guide to Six Sigma process improvement and variation reduction. Individuals studying to pass the ASQ Certified Six Sigma Yellow Belt (CSSYB) exam will find this comprehensive text invaluable for preparation, and it is also a handy reference for those already working in the field. The handbook offers a comprehensive understanding of the Body of Knowledge (BoK), which will allow readers to support real Six Sigma projects in their current or future roles.
This handbook, updated to reflect the 2022 BoK, - A detailed explanation of each section of the CSSYB BoK - Essay-type questions in each chapter to test reading comprehension - Numerous appendices, a comprehensive list of abbreviations, and a glossary of useful terms - Online contents, including practice exam questions - Source lists, which include webinars, tools and templates, and helpful publications
This is a good reference manual, but I don’t believe it’s a particularly good teaching handbook for someone preparing for their first CSSYB exam. It defines terminology well and maps concepts to the Body of Knowledge, but it frequently tells the reader what something is without adequately demonstrating how to apply it.
A handbook should serve as a practical guide, explaining not only what concepts are, but also how to use them. I expected the ASQ Certified Six Sigma Yellow Belt Handbook (2nd Edition) to provide that level of instruction. Instead, I found it to be much more of a glossary or reference manual than a teaching resource.
To its credit, the handbook does a solid job defining industry terminology and highlighting connections to the Body of Knowledge. However, it often stops at definitions without providing sufficient explanation or worked examples to help readers understand how to apply the concepts in practice. Considering the price is comparable to many collegiate textbooks, I expected considerably more instructional content.
Adding to that disappointment, the book is copyrighted in 2022, yet many of the supplemental digital resources date back as far as 2011.
One example is the discussion of stratification (p. 62). The text spends most of the section listing potential manufacturing and service-industry data sources before concluding that “stratification is a data mining approach to help dissect data by variables.” After nearly a page of setup, the reader is left without a meaningful demonstration of what stratification actually looks like or why it is useful. A simple worked example showing how data changes when stratified would have made the concept immediately understandable.
The most concerning issue, however, is an apparent mathematical error in the handbook itself.
On page 63, the handbook defines DPMO using the following equation:
(Total number of defects ÷ Total number of units × Number of opportunities per unit) × 10⁶
Using the manufacturing example immediately below the equation (10 defects, 100 units, and 4 opportunities per unit), evaluating the expression according to the standard order of operations produces:
(10 ÷ 100 × 4) × 10⁶ = 400,000
However, the handbook states the answer is 25,000 DPMO, which corresponds to the equation:
Defects ÷ (Units × Opportunities per Unit) × 10⁶
Unless the handbook establishes a notation convention elsewhere that makes the multiplication part of the denominator, the printed equation appears to be incorrect. This inconsistency is especially problematic in a certification handbook.
During my exam, I spent nearly fifteen minutes trying to reconcile why the handbook’s published equation wasn’t producing any of the available answer choices. It wasn’t until later that I realized the worked example contradicted the printed formula. For a timed certification exam, that kind of inconsistency can materially affect a candidate’s performance. Notably, my copy is the third printing of the second edition, suggesting this discrepancy has survived multiple print runs without correction.
Despite these criticisms, the handbook is a useful reference once you’re already familiar with the material. I simply would not recommend it as a stand-alone learning resource for someone encountering Six Sigma concepts for the first time. With more worked examples, practical applications, and greater editorial attention to mathematical accuracy, it could become the excellent resource its title suggests.