CPE 412 SIMULATION and MODELING n Instructor: Dr. Mahmoud Alrefaei n Various notes and transparencies can be found on web page.

What is Simulation n Simulation is a realization of a representation of larger and more complex activity. n An Activity is a system n Simulation uses model for representing the activity (system). n Realization means to make things look like real. n Example: Aircraft Simulator. Manufacturing System. Computer Networks, etc.

Alternative Definition n Simulation is pretending doing something in order to understand, analyze, and predict the future of systems behavior.

Systems and Models n System: is a set of interacting components or entities that interact together to achieve some task. n Examples of simulations include: u Hospitals u Telecommunications system u Highways u Computer Networks u Airport check in and Boarding facilities. u A Fast food restaurant.

n The state of the system: is a collection of variables needed to describe the system at some point of time. n Discrete and Continuous systems:  Discrete: when the state variables change at discrete point of times.  Example: a Bank ( the number of customers in the bank change at discrete points when a customer arrives or departs)  Continuous: when the state variables change continuously.  Example: the quantity of fluid in a tank as it leaks

Models A simplified representation of a system intended to enhance our ability to understand, predict, and possibly control the behavior of the system n It represents the most system components and the way they interact.

Types of Models Physical models: Like a model of house, bridge, car, …etc Mental models: Personal view of a foreign country, or an event or object. Symbolic models: Mathematical models maps graphs words (as in newspaper) pictures

How to Study Systems n Experiment with the actual system if possible n Experiment with a model of the system  Physical Model  Mathematical Model o Analytical Solution o Simulation

How to study systems System Experiment with with the actual System Experiment with a model of the system Type title here Physical modelMathematical Model Analytical SolutionSimulation

When to Use Simulation n The system does not exist. n Experimentation with real system is expensive n There is a need to study the past, present and the future behavior of the system in real time. n Mathematical Models are impossible. n Mathematical Models exist but have no analytical solution. n Results of Simulation are possible. n Expected accuracy of simulation results is consistent with the given problem.