2 Framework for Modeling and Simulation

This chapter is devoted to establishing a Framework for Modeling and Simulation (M&S). The framework defines entities and their relationships that are central to the M&S enterprise. Understanding these concepts will help everyone involved in a simulation modeling project − analysts, programmers, managers, users − to better carry out their tasks and communicate with each other. Terms such as “model” and “simulator” are often loosely used in current practice but have a very sharp meanings in the framework we will discuss. Therefore, it is important to understand what is included and excluded by the definitions. (This is especially true if you have some experience in M&S and are likely to associate (or prefer) meanings that are different from those developed here.) As illustrated in Figure 1, the basic entities of the framework are: source system, model, simulator and experimental frame. The basic inter-relationships among entities are the modeling and the simulation relationships, The entities are defined in Table 1. This table also characterizes the level of system specification that typically describes the entities. The level of specification is an important feature for distinguishing between the entities, which is often confounded in the literature. You can return to Figure 1 and Table 1 to keep an overall view of the framework as we describe each of the components in the following presentation.