What is Root Cause Analysis (RCA)? It seems like such an easy question to answer, yet from novices to veterans and practitioners to providers, we cannot seem to agree (nor come to consensus) on an acceptable definition for the industry. Why? We will discuss our beliefs as to why it is so hard to get such consensus and why various providers are reluctant for that to happen. Many who will read this text are seeking to learn the basics about what is involved with conducting an RCA. Many veterans will peruse this text seeking to see if they can find any pearls of conventional wisdom that they do not already know or to dispute and debate our philosophies. This creates a very broad spectrum of expectation that we will try to accommodate. However, in the end, success shall be defined by the demonstration of quantifiable results and not on adherence to the approach of favor. We tried to write this text in a conversational style because we believe this is a format that most “rooticians” can relate to. Basically, we wrote like we were teaching a workshop. Readers will find that much of our experience comes not only from the practicing of RCA in the field, but more so from our experiences with the over 10,000 analysts whom we have taught and mentored over the years. Additionally, we participate in many on-line discussion forums where we interact with beginners, veterans, and most providers for the betterment of the RCA field. We list these sources in this text in the hopes that our readers will join and also participate in progressing our common field of study. So as you can see, we try to bring many diverse perspectives to the table, while making the pursuit of RCA a practical one, not a complex one. We certainly want to avoid falling into the “paralysis-by-analysis” trap when looking at something like RCA—that would be hypocritical, would it not? We bring to light the perspectives of the pragmatic “rooticians” to the “purists” so that readers can make their own judgments as to what is best for their applications. We present debates on definitions of words commonly used in the RCA lexicon, but ultimately come to the conclusion that there are no generally accepted definitions in the field so we must fend for ourselves (which is part of the problem with communication). There are many RCA methodologies on the market and we discuss them in generalities so as not to put the microscope on any individual or proprietary approach. In this manner we can discuss the pros and cons of each type of approach, and readers can decide the level of breadth and depth that they require in their analysis. We discuss the scope of RCA—where does it begin and where does it end? How does a true RCA effort integrate with the organizational structure and remain a viable and valuable resource to the organization? Where there is RCA there is turf politics, so we discuss how this activity called RCA fits with existing initiatives like Total Quality Management (TQM), Reliability Engineering (RE), Reliability Centered Maintenance (RCM), and Six Sigma. Our intent with this edition of this text is to expand the various perspectives brought to light on the topic of RCA and to present a current “state-of-the-RCA field” so that readers can make their own sound judgments as to how they wish to design and define RCA for their own organizations. Will everybody who reads this text agree with its content? No. Can they benefit regardless? Yes. We hope to spark debate within the minds of our readers where the differences are contrasted between how we approach RCA and how they are currently conducting them at their facilities. Perhaps we will sway some to agree with certain premises in this text, and others will improve upon their current approaches with the ideas presented. Either way, the journey of the learning is what is most important. Analysts will collect the necessary data, sift out the facts, and make their own determination as to what they believe is best for them.