What is Simulation?

An Overview of Simulation and Modelling

The terms “modelling” and “simulation” are sometimes used interchangeably. In reality, they are distinct, though related, terms.

MODELLING is the representation of an object or phenomena, which is used by simulation. Models may be mathematical, physical, or logical representations of a system, entity, phenomenon, or process. Models are, in turn, used by simulation to predict a future state.

Examples of models:

  • Mathematical model of sensor response
  • Computer aided design model of an armoured vehicle or a helicopter or a human being

Modelling refers to the process of creating models.

SIMULATION is a representation of the functioning of a system or process. Through simulation, a model may be implanted with unlimited variations, producing complex scenarios. These capabilities allow analysis and understanding of how individual elements interact and affect the simulated environment.

Example of a simulation: 

  • three-dimensional model of an armoured vehicle which moves across a model of terrain over time

The tool that executes the simulation is a "simulator".

Live Simulations - Real people operate in the real world.
Virtual Simulations - Real people operate in synthetic worlds.
Constructive Simulations - Simulated entities operate in synthetic worlds.
Undefined Simulations - Simulated entities are subjected to real world environments.

Applications of Simulation: Experimentation, Operational Planning, Training, Missions Rehearsal, Support to the Conduct of Operations, Life Cycle Management.

Generally, people most readily associate Modelling and Simulation (M&S) with training. M&S tools are used to train astronauts, commercial and military aircrews, nuclear power specialists, healthcare workers, and maintenance specialists, just to name a few professionals. M&S provides rehearsal environments for civilian first responder and military personnel. Repeated rehearsal of procedures improves performance, saving countless lives as well as aircraft, ships, and other vehicles. Also, training individuals before allowing them to use actual equipment improves the safety of the individuals undergoing training, the participants around them and the safety of the actual equipment.

While training is perhaps the most visible of M&S applications, M&S can be used to study any system or process. This ranges from human bodily systems and transportation networks, to vehicle systems, communities, and product design or manufacturing. M&S tools and processes help solve pressing issues across government, industry, and academic domains. M&S can answer “what if” questions or provide a robust experimentation or training environments that may not be otherwise realised.

Fundamental Concepts in Simulation

Learning the language is a key task facing everyone who is entering any new field of work, especially one such as simulation, which has both technical and educational aspects.  When we are engaged in learning through use of a simulation we might find towards in any one of a number of quite different contexts. In one setting we may be taking part in a face-to-face role-based activity, drawing on individual interpretations of some aspect of real world conditions. In another setting we might have a role as a member of a team that has the task of using a technical simulation to create learning environments, using data obtained through analysis of the real world. Both of these are using ‘simulation’ to create a learning context and each uses the same core essentials to do so. However the visible setting may be quite different and reliance on different technologies may even obscure the similarities between them.

Designing Instructional/Learning Components of Simulation

The initial design basis for all training/learning involving any use of a simulation is instructional design. The process does not begin with the technology, although sometimes it is hard to convince clients that the technology to be used is not the beginning point. In the past sixty years there have been tremendous advances in instructional design and simulation development and both of these must be taken advantage of as much as possible to create truly engaging learning environments.  All sectors of the simulation design and construction process are becoming more aware of this as divisions separating engineering, learning and support are dissolving in the face of the need to address ever more complex learning outcomes through integrated use of face to face and technical simulation.

VV&A - Verification, Validation and Accreditation

Verification, Validation and Accreditation is a trio of concepts vital to assuring that any simulation meets relevant quality control criteria. They are used together as a means of putting a simulation ‘through its paces’ prior to committing it to use.


Standards for simulation and modelling are essential to tasks such as the conduct of VV&A and simulator interoperability.  But they can impose costs and limit the capability of simulation, so should only be used where the benefits outweigh the costs.