O. Thomas Holland
There can often be a great deal of confusion when one first encounters the terminology associated with systems engineering, operations research, software engineering, or computer modeling. This confusion is especially vexing when these domains converge in model-based systems engineering as in the development or analysis of military systems. In this paper we attempt to make clear the definitions and usage of many commonly encountered terms, emphasizing the distinction of these terms especially within the context of the military domain. We will examine the general use of these terms along with the corresponding academic or professional community language and attempt to synergize these with their Department of Defense usage. In many cases we will see that there is not as much difference as we might have at first thought. References are used throughout, although the exact statement of a definition will usually not be a direct quote if a combination of sources produces a synthesis that is more understandable. This summary is intended for those who find themselves working in the model-based systems engineering domain, especially in a Department of Defense related context. It is our hope that this will be useful to those who want to better understand certain fundamental terms or are struggling to ascertain what terms apply to their needs and when a new term might be needed. The references cited provide many additional details if more information is desired.