Types of Simulation Models - Yousef's Notes
Types of Simulation Models

Types of Simulation Models

The simulation model you choose will depend upon the System you are trying to understand.

#Deterministic vs Stochastic

A deterministic model is a model whose behavior is entirely predictable. Given a set of inputs, the model will always result in a unique set of outputs.

A stochastic or probabilistic model is a model that has random variables as inputs, and consequently its outputs are random.

For example: In a donut shop simulation, with a deterministic model, we would assume that a new customer arrives every 5 minutes and an employee takes 2 minutes to serve a customer. In a stochastic/probabilistic model we would assume that the arrival times and the serving time follows some random variables like the normal distribution.

#Static vs Dynamic

Simulation models that represent the system only at a particular point in time are called static. This type of simulations are often called [[Monte Carlo Simulation in Python | Monte Carlo simulations]].

Dynamic simulation models represent systems that evolve over time. The simulation of the donut shop during its working hours is an example of a dynamic model.

#Discrete vs Continuous

Dynamic simulations can be further categorized into discrete or continuous.

In Discrete simulation models, the variables of interest change only at a discrete set of points in time. The number of people queuing in the donut shop is an example of a discrete simulation. The number of customer changes only when a new customer arrives or when a customer has been served.

For specific periods of times, the system doesn’t change state. Therefore, time is handled using the next-event technique. The model is only examined and updated when the system is due to change. These changes are usually called events.

In Continuous simulation models, the variables of interest change continuously over time.

e.g. a simulation model for a car journey where the interest is on the speed of the car throughout the journey.