Definition
In M&S, a Model is a representation of an event and/or thing that is real (a case study) or contrived (a use-case). It is an abstraction from reality designed to represent a system at a specific point or multiple levels of abstraction in a mathematically or symbolically reliable fashion.
Why It Matters
Confusion about what a model ‘is’ versus what it ‘represents’ leads to the ‘map-territory’ fallacy. If we forget that a model is a simplification, we over-rely on its predictions and fail to account for the complexity of the real world, leading to fragile systems.
Core Concepts
- Abstraction: The intentional omission or reduction of detail not considered necessary for the model’s intended application.
- Fidelity: The degree of a model’s accuracy with respect to the represented Simuland. Accuracy and fidelity are often used interchangeably.
- Types of Models:
- Conceptual Model: A non-executable documentation (equations, flowcharts, UML) that defines what aspects of the simuland are represented.
- Executable Model: A model that can be run (typically a computer program) based on the conceptual model’s specifications.
- Simuland: The real-world system of interest (object, process, or phenomenon) being simulated.