Overview

Systems engineering ^[1] methodologies and practices began to emerge from experience gained in the U.S. Department of Defense (DoD) acquisition programs of the 1950s. These programs often involved complex and challenging user requirements that tended to be incomplete and poorly defined. Additionally, most programs entailed high technical risk because they involved large numbers of different technical disciplines and the use of emerging technology. Following a number of program failures, the discipline of systems engineering emerged to help avoid, or at least mitigate, some of the technical risks associated with the complex equipment acquisition programs. Systems engineering provides a framework, within which complex systems can be adequately defined, analyzed, specified, manufactured, operated, and supported. Systems engineering processes and methodologies have continued to develop since the 1950s and are widely applied to many of today's challenging acquisition projects.

The focus of systems engineering is on the system as a whole and the maintenance of a strong interdisciplinary approach. Project management, quality assurance, integrated logistics support, and traditional design disciplines such as hardware and software engineering are but a few of the many disciplines that are part of a coordinated systems engineering effort.

Throughout the following chapters, we use a number of examples wherever possible to illustrate and reinforce the systems engineering theory being introduced. To avoid duplication and assist further with an understanding of the whole systems engineering process, throughout the chapters we also use a single worked example, based on the acquisition of an aircraft system. We do not...