16-11-2012, 04:27 PM
CSL403 Introduction To Modeling and Simulation
CSL403 Introduction.ppt (Size: 766 KB / Downloads: 35)
Goals Of This Course
Introduce Modeling
Introduce Simulation
Develop an Appreciation for the Need for Simulation
Develop Facility in Simulation Model Building
“Learn by Doing”--Lots of Case Studies
What Is A Model ?
A Representation of an object, a system, or an idea in some form other than that of the entity itself.
What is Simulation?
A Simulation of a system is the operation of a model, which is a representation of that system.
The model is amenable to manipulation which would be impossible, too expensive, or too impractical to perform on the system which it portrays.
The operation of the model can be studied, and, from this, properties concerning the behavior of the actual system can be inferred.
Definition:
Simulation is the process of designing
a model of a real system and conducting
experiments with this model for the
purpose of either understanding the
behavior of the system and/or
evaluating various strategies for the
operation of the system.
Allows us to:
Model complex systems in a detailed way
Describe the behavior of systems
Construct theories or hypotheses that account for the observed behavior
Use the model to predict future behavior, that is, the effects that will be produced by changes in the system
Analyze proposed systems
Brief History
“Monte Carlo” simulation: originated with
the work on the atomic bomb. Used to
simulate bombing raids. Given the
security code name “Monte-Carlo”.
Still widely used today for certain problems
which are not analytically solvable (for
example: complex multiple integrals…)
Applications:
COMPUTER SYSTEMS: hardware components, software
systems, networks, data base management, information
processing, etc..
MANUFACTURING: material handling systems, assembly
lines, automated production facilities, inventory control
systems, plant layout, etc..
BUSINESS: stock and commodity analysis, pricing policies,
marketing strategies, cash flow analysis, forecasting, etc..
GOVERNMENT: military weapons and their use, military
tactics, population forecasting, land use, health care
delivery, fire protection, criminal justice, traffic control, etc..
Examples of Applications at Disney World
Cruise Line Operation:
Simulate the arrival and
check-in process at the dock. Discovered the
process they had in mind would cause hours
in delays before getting on the ship.
Private Island Arrival:
How to transport passengers
to the beach area? Drop-off point far from the
beach. Used simulation to determine whether
to invest in trams, how many trams to purchase,
average transport and waiting times, etc..
Advantages to Simulation:
Can be used to study existing systems without disrupting the
ongoing operations.
Proposed systems can be “tested” before committing resources.
Allows us to control time.
Allows us to identify bottlenecks.
Allows us to gain insight into which variables are most
important to system performance.
Disadvantages to Simulation
Model building is an art as well as a science. The quality
of the analysis depends on the quality of the model and the
skill of the modeler (Remember: GIGO)
Simulation results are sometimes hard to interpret.
Simulation analysis can be time consuming and expensive.
Should not be used when an analytical method would
provide for quicker results.