Chapter 23 1
A model is a program which has been
developed to copy the way a system
works in real life.
It uses mathematical formulas and
calculations to predict what is likely to
happen based on data recorded about
what actually did happen in the past.
A modeling is a set of equations
which describes the behavior of
Chapter 23 2
You can develop and evaluate your own models or
use the models that have already been set up to
simulate a real life
Supply and demand
Chapter 23 3
Expert System & Expert Builder
Expert system are programs
that mimic the intelligence of
human expert in a specific
field of knowledge.
Could be set up to give
The computer is given a base
of knowledge from the expert
and then given the rules for
Computer ask the questions
similar to those the expert
would ask and then comes to
That enables you to
construct logical diagrams of
your knowledge .
This software helps you to
understand a problem more
Chapter 23 4
A simulation is a software package that recreates
or simulates a complex phenomena,
environment, or experience in order to provide the
user with a better understanding.
A simulation is interactive, and relies upon
decisions made by the user, often in ‘real time’.
Simulation uses computer modelling in order to
The difference between a model and a
simulation is that a simulation also uses
something physical to mimic the system.
Chapter 23 5
Thrill ride simulator somewhere like Disneyland.
Another form of simulation is Virtual Reality.
Experiments in chemistry
Traffic lights Systems
Nuclear physics experiments
Common uses of simulations include:
3D Engineering simulations.
Chapter 23 6
Computer games are simulations of various
types of experience.
They have five elements:
Graphics (often 3D and sometimes incorporating Full
Motion Video [FMV]).
Sound (including music and sound effects).
An interface (usually the keyboard or a joystick but
also including the graphics, the menu, and the Artificial
Intelligence [AI] incorporated into the game’s
Game play (including fun and length of playability).
Scenario (the background to the game and any
information or understanding that the player gathers
Chapter 23 7
Flight simulators are used to train pilots
how to fly.
They can also be used to test new
aircraft before they are actually flown for
the first time.
Flight simulators are expensive to buy
but are much cheaper than actual aircraft.
A landing simulation with ice on the
runway, thick fog and only one of the four
engines working would really test the
Chapter 23 8
Economic models are used by governments
and businesses to see what would happen if
changes occurred in the economy.
For example, the government might want to
see what would happen if they changed the
level of tax on fuel – Would prices increase?
Would road haulage companies go out of
Chapter 23 9
3D Engineering simulations
3D Engineering simulations can be
used to design new products (e.g.
cars) or to test existing products
(e.g. Nuclear power stations, oil
refineries, aircraft) in ways that
would be too expensive or too
dangerous to do in real life.
Simpler versions can also be used
to help people to sell products (e.g.
new kitchens), where potential
buyers want to see what the
finished product will look like.
Chapter 23 10
Advantages of Models
No equipment is damaged
People aren't put in any danger
Expensive prototypes don't need to be built
Time can be sped up or slowed down
Models can be run and re-run over and over
Modifications can easily be made and re-
Chapter 23 11
Disadvantages of Models and Simulations
The results depend on how good the model is and
how much data was used to create it in the first
Models and simulations can't ever completely re-
create real-life situations.
Not every possible situation may have been
included in the model.
The equipment and software are expensive to
Staff need to be trained how to use the software