* A software program that runs on any computer that attempts to simulate some phenomenon based on a scientist's conceptual and mathematical understanding of the given phenomenon.

* The scientist's conceptual understanding is reduced to an algorithmic or mathematical logic, which is then programmed in one of many programming languages (Fortran, C, C++, etc.) and compiled to produce a binary code that runs on a computer.

* Have become a useful part of modeling many natural systems in physics, chemistry and biology, human systems in economics and social science and in the process of engineering new technology, to gain insight into the operation of those systems

Areas that Uses Simulation

* Designing and analyzing manufacturing systems;

* Evaluating military weapons systems or their logistics requirements; * Determining hardware requirements or protocols for communication networks; * Determining hardware and software requirements for a computer system; * Designing and operating transportation systems such as airports, freeways, ports, and subways; * Evaluating designs for service organizations such as call centers, fast-food restaurants, hospitals, and post offices; * Reengineering of business processes;

* Determining ordering policies for an inventory systems; and, * Analyzing financial or economic systems.

Model

* is a representation of the construction and working of some system * similar to but simpler than the system it represents.

* for a simulation study, a model is a mathematical model developed with the help of a simulation software.

Computer Model

* is a computer program which attempts to simulate an abstract model of a particular system

Why use a model?

* cheaper

* safer

* saves time than real system

When to use simulation?

* systems that changes with time

* systems that involves randomness

Impediments on the use of Simulation:

* models used to study large-scale systems tend to be very complex * large amount of computer time is sometimes required.

* simulation is an exercise in computer programming.

System

* collection of entities that act and interact together toward the accomplishment of some logical end. * the collection of entities that comprise a system of one study might only be a subset of the overall system for another. * example: bank

State of the system

* the collection of all variables necessary to describe a system at a particular time, relative to the objectives of the study.

System Categories

* into two types:

* Discrete

* is a system for which the state variable changes instantaneously at separated points in time. * Bank

* Continuous

* is one for which the state variable changes continuously with respect to time. * Airplane moving through the air

Ways to study a system

* Model Classification

* Static vs. Dynamic Simulation Models

* Deterministic vs. Stochastic Simulation Models

* Continuous vs. Discrete Simulation Models

Static vs. Dynamic Simulation Model

* Static simulation model

* is a representation of a system at a particular time, or one that may be used to represent a system in which time simply plays no role. * Monte Carlo model

* Dynamic simulation model

* represents a system as it evolves over time

* Conveyor system in a factory.

Deterministic vs. Stochastic Simulation Model

* Deterministic simulation model

* this is used if the simulation model does not contain any probabilistic components. * in here, the output is “determined” once the set of input quantities and relationships in the model have been specified. * use of complicated differential equation to determine a chemical reaction of a particular element.

* Stochastic simulation model

*...