Complex Systems + Systems Engineering = Complex Systems Engineeri

One may define a complex system as a system in which phenomena emerge as a consequence of multiscale interaction among the system’s components and their environments. The field of Complex Systems is the study of such systems—usually naturally occurring, either biological or social. Systems Engineering may be understood to include the conceptualising and building of systems that consist of a large number of concurrently operating and interacting components—usually including both human and non-human elements. It has become increasingly apparent that the kinds of systems that systems engineers build have many of the same multiscale characteristics as those of naturally occurring complex systems. In other words, systems engineering is the engineering of complex systems. This paper and the associated panel will explore some of the connections between the fields of complex systems and systems engineering. What do complex systems and systems engineering have in common? A complex system—in the sense of the word as used to identify the field of study by that name—typically consist of elements that operate asynchronously. These elements operate according to their own schedules and are not all entrained by a single overall timing driver, i.e., a driver whose rate is transmitted throughout the system by mechanisms such as gears, drive shafts, belts, electronic timing signals, etc. Complex systems tend to exhibit what are often referred to as multiscale or emergent phenomena: phenomena at an aggregate level that (a) result from and (b) are a consequence of but (c) may be described independently of how the interactions among the individual elements bring them about. See (Abbott 2005). Large-scale engineered systems typically consist of many concurrently operating and interacting elements—human and non-human—which as an ensemble either produce a result or provide a service or set of services. Such systems exhibit similar emergent and multiscalar properties. It has become increasingly clear that systems engineering is the engineering of complex systems. Although this realization is by now fairly widely shared, at least implicitly, and although complex systems ideas, tools, and techniques have been applied to systems engineering problems for some time, there has been little effort to date to bring the two fields—and the communities of people who work in these fields—together in a more formal and explicit way. The current CSER session is the first in a series of events whose goal is to introduce these communities to each other and to embark on what we expect to be an extended dialog. Following this CSER session, sessions will be held at the IEEE System of Systems Engineering Conference (April 2006) and at the INCOSE Symposium (July 2006). A stand-alone workshop on Complex Systems Engineering is being planned for January 2007 to be followed by a full conference at which revised papers from that workshop (along with other submitted papers) will be presented to a larger audience. The follow-on conference will be sited and scheduled to coordinate with the INCOSE 2007 Symposium. What issues are of interest to both complex systems and systems engineering? In forging a connection between systems engineering and complex systems, the questions to be addressed may be summarized as follows. • What does systems engineering need from complex systems? What difficulties have large (and complex) engineered systems encountered that seem to derive from the fact that they are complex in the sense described