Hopp/Spearman have built and improved an essential guide to the fundamental principles of operations analysis. After years of hearing Factory Physics praised by my Industrial Engineering colleagues, I finally got it. As a practitioner and teacher I cannot overstate that this is essential knowledge of the dynamics of operating systems. Most of us don't get what's going on in our operations. Hopp &amp; Spearman not only explain it, they provide the equations!  I also greatly appreciate the historical perspective provided in Part I. Having lived operations through this time period, not only is it quite accurate, but also I find this perspective to be particularly helpful for new learners. Part II does well to explain what is really going on in operating systems and, for math nerds, lays out all the equations. Hopp/Spearman do well to provide simple systems to demonstrate these calculations, and refer back to these examples to reinforce principles later in the text. Part III adds more detailed guidance of applications of the principles in today's operating environment. All of this is presented in a pleasant writing style that is easy to read. This wisdom appears somewhat unique in the discipline and provides insights into understanding our complex operating environments that is seldom seen in other sources.