Synergy of Systems Engineering and Modeling and Simulation Tuncer I. Ören M&SNet: OC-MISS (Ottawa Center of the McLeod Institute of Simulation Sciences) SITE, University of Ottawa Ottawa, ON, Canada oren@site.uottawa.ca Levent Yilmaz M&SNet: AMSL (The Auburn Modeling and Simulation Laboratory) Computer Science and Software Engineering Auburn University Auburn, AL, USA yilmaz@auburn.edu Abstract The shift of paradigm in modeling and simulation studies of large and complex systems, namely synergy of M&S and systems engineering is explained. 1. INTRODUCTION We are witnessing an important paradigm shift in simulation of large and complex systems. This paradigm shift is taking advantage of the synergy of modeling and simulation (M&S) and systems engineering (SE) which has a common characteristic: they are not an end by themselves. However, they are vital in solving real and important problems. M&S is applicable to simple as well as to complex and large scale system problems, including systems of system problems. SE is applied to moderate to very complex and large scale system problems. M&S and SE are mutually beneficial. Even in the 1960s, M&S was very useful in SE by providing virtual labs to study system problems. There are many cases, especially in the studies of large and complex systems where M&S is vital for the success of the project; however, ignoring SE in such projects may be detrimental to the success of the project. Hence, several institutions active in the deployment of complex and large scale systems started to have groups jointly active in SE and M&S. SE is also very useful in areas other than M&S, such as software engineering as software systems engineering, even though SE and software engineering are distinct disciplines. Similarly, it appears that time is ripe for a closer synergy of SE and M&S to solve complex and large scale system problems. This may lead to simulation systems engineering (SSE) while still keeping both SE and M&S as distinct disciplines. The article covers the following: Section 2 provides a review of some pertinent aspects of M&S; this includes scope and perspectives of M&S, importance of M&S and associated responsibilities, increasing complexity of both M&S systems and M&S applications, and life cycle of M&S. Section 3 is on systems engineering and covers definitions of systems and systems engineering, SE tasks and life cycle, and highlights of role of SE in some disciplines. Section 4 is on synergy of M&S and SE, and includes M&S for Se, SE for M&S, and M&S and SE. Section 5 is for conclusions. Extensive references are given and the appendix covers the essential tasks of systems engineering. 2. Modeling and Simulation (M&S) M&S, as a discipline, is vital for the success of many applications areas in a multitude of disciplines (Ören 2002a). In this article, due to space limitation, we focus on the scope of M&S, importance of M&S and associated responsibilities, and especially on the increasing complexity of both M&S systems and M&S applications which leads to the requirements of the synergy of SE and M&S. The subsection on the M&S life cycle is provided to draw the parallels between the life cycle of M&S and the major tasks of systems engineering. More references on different aspects of M&S can be found at the website of the Body of Knowledge of M&S (M&SBOK) which is being developed under the auspices of the National Training and Simulation Association (NTSA). 2.1 Scope of M&S M&S has many facets; often specialists in one area have a tendency to ignore other aspects. At one extreme this leads the point of view of “Anything other than war is simulation” (STRICOM). Of course, this point of view stressing on the main task is