In our modern landscape of large-scale complex systems, we need to think critically to solve problems. Applied critical thinking exercises reason, which becomes our most important resource and must be put to work. The ability to effectively solve problems, particularly in complex situations, is the hallmark of one who can think critically. Moving the critical thinking process into the realm of operational systems, this handbook delves into analytic reasoning. Analytic reasoning is especially useful in dealing with large-scale dynamic systems that exhibit high levels of complexity. Such systems are essential in our modern industrial society. Quick, easy, and inexpensive problem solving is preferred by many today, but this is an illusion and in complex situations this is a prescription for disaster. This Critical Thinking Essentials Handbook, prepared especially for operators and managers, provides as a key feature a distinct operational orientation that makes it useful for serious challenges concerning complex situations and the operation of large-scale dynamic systems.