This book concentrates on the engineering of human-made systems and on systems analysis. In the first case, emphasis is on the process of bringing systems into being, beginning with the identification of a need and extending through requirements determination, functional analysis and allocation, design synthesis, evaluation, and validation, operation and support, phase-out, and disposal. In the second case, focus is on the improvement of systems now in being. By employing the iterative process of analysis, evaluation, feedback, and modification, most systems in existence can be improved in their affordability, effectiveness, and stakeholder satisfaction. The authors present and demonstrate the utilization of various analytical models and methods for accomplishing system analysis, not only in the design and evaluation of new systems, but in the evaluation of existing systems for the purpose of their improvement. Also emphasized is the need to properly integrate a variety of engineering design and management disciplines to effectively implement the concepts and principles of systems engineering.