-The Art of Managing Complexity-
Submitted on October 16th, 2001, for ESD.83
Cory R.A. Hallam
Systems Engineering has emerged as a distinct professional discipline in the past half century in response to the ever-increasing complexity of new products and systems. This paper provides a brief overview of the discipline and the role of theSystems Engineer.
The term Systems Engineering (SE) is a generic term that describes the application of structured engineering methodologies to the design and creation of complex systems. While there has been great discussion about the term "system", it can be argued that from the point of view of the System Engineer, a system is a collection or set of "parts" that work together toperform a particular function. These parts can be in the form of hardware, software, or liveware, and in themselves may be considered systems. The system definition is essentially relative to the perspective of the individual who views the system. The discipline of Systems Engineering focuses on the coordination of all of the disciplines, tasks, and activities necessary to develop the total system.Unlike traditional engineering disciplines, such as hydraulics engineering, structural engineering, or electrical engineering, Systems Engineering is not governed by a set of fundamental mathematical relations based on physical properties. In essence, it has not traditionally been a strict laboratory-based form of engineering. It has emerged from a need to deal with the ever-increasingcomplexity of system development projects, and emerged as a collection of best-practices for managing the development of complex engineering systems. Given the ad-hoc assemblage of many of these best-practices in their early years, the past several decades has seen the application of modeling and simulation tools to the development of processes that optimize system development in multivariate systemrequirements space - a process that historically was an emergent property of multiple iterations in managing, designing, and creating complex systems. The current state of affairs in System Engineering seems to support the notion that Systems Engineering ultimately attempts to formalize the process of tracing and managing customer requirements from conceptual design through to system development andoperation.
Historical Basis for Modern System Engineering
The field of System Engineering as we know it emerged from the post World War II (WWII) military-industrial-academic complex that was embroiled in an accelerating weapons race with the former Soviet Union. While many pre-WWII systems were designed, built and implemented in a succession of steps with relatively few decision makersaffecting the technical design and development of the system, post WWII military projects were inherently more complex involving exponentially increasing numbers of disciplinary experts and increasing layers of interacting systems of systems. The foundation of System Engineering, as it is known today, emerged from this era via the Atlas Intercontinental Ballistic Missile (ICBM) Program.
Prior tothe Atlas ICBM program, the U.S. Air Force (Army Air Corp in earlier years) dealt with prime airframe contractors who were responsible for designing an aircraft to military specifications and managing all of the subcontractors necessary for delivering on the contract. This led to an environment of airframe-centric military platforms that senior Air Force officials became accustomed to purchasingand managing on a 1-to-1 basis with the prime. Ultimately, this resulted in a limited number of military weapons system options, as the decision of using an airframe platform was essentially never questioned. When the time came for the development of an ICBM in the early 1950's, the Air Force was again poised to choose an airframe manufacturer and pursue a prime contractor relation.