Introduction to Simulation: Lesson 2

Introduction to Simulation

• Simulation is the imitation of the operation of a real-world process or system over time, to develop a set of assumptions about the behavior of the system, and to estimate the measures of performance of the system with the simulation-generated data.
• Simulation modeling can be used as an analysis tool for predicting the effect of changes to existing systems and as a design tool to predict the performance of new systems.

When Simulation is the Appropriate Tool

• Simulation enables the study of, and experimentation with, the internal interactions of a complex system, or of a subsystem within a complex system.
• Simulation can be used to experiment with new designs or policies prior to implementation, to prepare for what may happen.
• Simulation can be used to verify analytic solutions.
• Simulation models designed for training allow learning without the cost and disruption of on-the-job learning.

When Simulation is not Appropriate

• When the problem can be solved using common sense.
• When the problem can be solved analytically.
• When it is easier to perform direct experiments.
• When the simulation costs exceed the savings.
• When the resources or time are not available.
• When system behavior is too complex or can’t be defined.
• When there isn’t the ability to verify and validate the model.

Advantages and Disadvantages of Simulation

Advantages

• New policies, operating procedures, decision rules, information flows, organizational procedures, and so on can be explored without disrupting ongoing operations of the real system.
• New hardware designs, physical layouts, transportation systems, and so on, can be tested without committing resources for their acquisition.
• Hypotheses about how or why certain phenomena occur can be tested for feasibility.
• Insight can be obtained about the interaction of variables.
• Insight can be obtained about the importance of variables to the performance of the system.
• Bottleneck analysis can be performed indicating where work-in-process, information, materials, and so on are being excessively delayed.
• A simulation study can help in understanding how the system operates rather than how individuals think the system operates.
• “What-if” questions can be answered.

Disadvantages

• Model building requires special training.
• Simulation results may be difficult to interpret.
• Simulation modeling and analysis can be time-consuming and expensive.
• Skimping on resources for modeling and analysis may result in a simulation model or analysis that is not sufficient for the task.
• Simulation is used in some cases when an analytical solution is possible, or even preferable.

Areas of Application

Manufacturing Applications

• Analysis of electronics assembly operations
• Design and evaluation of a selective assembly station for high-precision scroll compressor shells
• Comparison of dispatching rules for semiconductor manufacturing using large-facility models
• Evaluation of cluster tool throughput for thin-film head production
• Determining optimal lot size for a semiconductor back-end factory
• Optimization of cycle time and utilization in semiconductor test manufacturing
• Analysis of storage and retrieval strategies in a warehouse
• Investigation of dynamics in a service-oriented supply chain
• Model for an Army chemical munitions disposal facility

Semiconductor Manufacturing

• Comparison of dispatching rules using large-facility models
• The corrupting influence of variability
• A new lot-release rule for wafer fabs
• Assessment of potential gains in productivity due to proactive reticle management
• Comparison of a 200-mm and 300-mm X-ray lithography cell
• Capacity planning with time constraints between operations
• 300-mm logistic system risk reduction

Construction Engineering

• Construction of a dam embankment
• Trenchless renewal of underground urban infrastructures
• Activity scheduling in a dynamic, multiproject setting
• Investigation of the structural steel erection process
• Special-purpose template for utility tunnel construction

Military Application

• Modeling leadership effects and recruit type in an Army recruiting station
• Design and test of an intelligent controller for autonomous underwater vehicles
• Modeling military requirements for non-warfighting operations
• Multitrajectory performance for varying scenario sizes
• Using adaptive agent in U.S Air Force pilot retention

Logistics, Transportation, and Distribution Applications

• Evaluating the potential benefits of a rail-traffic planning algorithm
• Evaluating strategies to improve railroad performance
• Parametric modeling in rail-capacity planning
• Analysis of passenger flows in an airport terminal
• Proactive flight-schedule evaluation
• Logistics issues in autonomous food production systems for extended-duration space exploration
• Sizing industrial rail-car fleets
• Product distribution in the newspaper industry
• Design of a toll plaza
• Choosing between rental-car locations
• Quick-response replenishment

Business Process Simulation

• Impact of connection bank redesign on airport gate assignment
• Product development program planning
• Reconciliation of business and systems modeling
• Personnel forecasting and strategic workforce planning

Human Systems

• Modeling human performance in complex systems
• Studying the human element in air traffic control

Introduction to Simulation

• Simulation is the imitation of the operation of a real-world process or system over time, to develop a set of assumptions about the behavior of the system, and to estimate the measures of performance of the system with the simulation-generated data.
• Simulation modeling can be used as an analysis tool for predicting the effect of changes to existing systems and as a design tool to predict the performance of new systems.

When Simulation is the Appropriate Tool

• Simulation enables the study of, and experimentation with, the internal interactions of a complex system, or of a subsystem within a complex system.
• Simulation can be used to experiment with new designs or policies prior to implementation, to prepare for what may happen.
• Simulation can be used to verify analytic solutions.
• Simulation models designed for training allow learning without the cost and disruption of on-the-job learning.

When Simulation is not Appropriate

• When the problem can be solved using common sense.
• When the problem can be solved analytically.
• When it is easier to perform direct experiments.
• When the simulation costs exceed the savings.
• When the resources or time are not available.
• When system behavior is too complex or can’t be defined.
• When there isn’t the ability to verify and validate the model.

Advantages and Disadvantages of Simulation

Advantages

• New policies, operating procedures, decision rules, information flows, organizational procedures, and so on can be explored without disrupting ongoing operations of the real system.
• New hardware designs, physical layouts, transportation systems, and so on, can be tested without committing resources for their acquisition.
• Hypotheses about how or why certain phenomena occur can be tested for feasibility.
• Insight can be obtained about the interaction of variables.
• Insight can be obtained about the importance of variables to the performance of the system.
• Bottleneck analysis can be performed indicating where work-in-process, information, materials, and so on are being excessively delayed.
• A simulation study can help in understanding how the system operates rather than how individuals think the system operates.
• “What-if” questions can be answered.

Disadvantages

• Model building requires special training.
• Simulation results may be difficult to interpret.
• Simulation modeling and analysis can be time-consuming and expensive.
• Skimping on resources for modeling and analysis may result in a simulation model or analysis that is not sufficient for the task.
• Simulation is used in some cases when an analytical solution is possible, or even preferable.

Areas of Application

Manufacturing Applications

• Analysis of electronics assembly operations
• Design and evaluation of a selective assembly station for high-precision scroll compressor shells
• Comparison of dispatching rules for semiconductor manufacturing using large-facility models
• Evaluation of cluster tool throughput for thin-film head production
• Determining optimal lot size for a semiconductor back-end factory
• Optimization of cycle time and utilization in semiconductor test manufacturing
• Analysis of storage and retrieval strategies in a warehouse
• Investigation of dynamics in a service-oriented supply chain
• Model for an Army chemical munitions disposal facility

Semiconductor Manufacturing

• Comparison of dispatching rules using large-facility models
• The corrupting influence of variability
• A new lot-release rule for wafer fabs
• Assessment of potential gains in productivity due to proactive reticle management
• Comparison of a 200-mm and 300-mm X-ray lithography cell
• Capacity planning with time constraints between operations
• 300-mm logistic system risk reduction

Construction Engineering

• Construction of a dam embankment
• Trenchless renewal of underground urban infrastructures
• Activity scheduling in a dynamic, multiproject setting
• Investigation of the structural steel erection process
• Special-purpose template for utility tunnel construction

Military Application

• Modeling leadership effects and recruit type in an Army recruiting station
• Design and test of an intelligent controller for autonomous underwater vehicles
• Modeling military requirements for non-warfighting operations
• Multitrajectory performance for varying scenario sizes
• Using adaptive agent in U.S Air Force pilot retention

Logistics, Transportation, and Distribution Applications

• Evaluating the potential benefits of a rail-traffic planning algorithm
• Evaluating strategies to improve railroad performance
• Parametric modeling in rail-capacity planning
• Analysis of passenger flows in an airport terminal
• Proactive flight-schedule evaluation
• Logistics issues in autonomous food production systems for extended-duration space exploration
• Sizing industrial rail-car fleets
• Product distribution in the newspaper industry
• Design of a toll plaza
• Choosing between rental-car locations
• Quick-response replenishment

Business Process Simulation

• Impact of connection bank redesign on airport gate assignment
• Product development program planning
• Reconciliation of business and systems modeling
• Personnel forecasting and strategic workforce planning

Human Systems

• Modeling human performance in complex systems
• Studying the human element in air traffic control

This quiz covers the basics of simulation, including system classification and theory, and their relation to simulation. Test your understanding of the concepts learned in Lesson 2.