Operations Research, Systems Engineering and Industrial Engineering Commons^™

Intelligent Simulation-Based Lot Scheduling Of Photolithography Toolsets In A Wafer Fabrication Facility, Amr Arisha, Paul Young

Conference papers

Scheduling of a semiconductor manufacturing facility is one of the most complex tasks encountered. Confronted with a high technology product market, semiconductor manufacturing is increasingly more dynamic and competitive in the introduction of new products in shorter time intervals. Photolithography, being one of the processes repeated often, is a fabrication bottleneck. Lot scheduling within photolithography is a challenging activity where substantial improvements in factory performance can be made. The proposed scheduling methodology integrates two common approaches, simulation and artificial intelligence. Using detailed simulation modeling within a structured modeling method, a comprehensive model to characterize the photolithography process was developed. An …

A Template-Based Conceptual Modeling Infrastructure For Simulation Of Physical Security Systems, Ashu Guru, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

Although simulation is one of the most innovative and cost-effective tools for modeling and analyzing a system, simulation studies often fail to provide any useful results. One reason is attributed to the fact that model formulation depends on the skills of the analyst. This paper describes a research to develop a conceptual modeling infrastructure to assist a simulation analyst in specifying components for studying physical security systems. The modeling framework has been programmed as an internet-based web application. Using the application, the successful development and implementation of a physical security simulation model will be aided by a defined scientific methodology …

A Template-Based Conceptual Modeling Infrastructure For Simulation Of Physical Security Systems, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

Although simulation is one of the most innovative and cost-effective tools for modeling and analyzing a system, simulation studies often fail to provide any useful results. One reason is attributed to the fact that model formulation depends on the skills of the analyst. This paper describes a research to develop a conceptual modeling infrastructure to assist a simulation analyst in specifying components for studying physical security systems. The modeling framework has been programmed as an internet-based web application. Using the application, the successful development and implementation of a physical security simulation model will be aided by a defined scientific methodology …

Bezier Curves For Metamodeling Of Simulation Output, Harish J. Kingre

LSU Master's Theses

Many design optimization problems rely on simulation models to obtain feasible solutions. Even with substantial improvement in the computational capability of computers, the enormous cost of computation needed for simulation makes it impractical to rely on simulation models. The use of metamodels or surrogate approximations in place of actual simulation models makes analysis realistic by reducing computational burden. There are many popular metamodeling techniques such as Polynomial Regression, Multivariate Adaptive Regression Splines, Radial Basis Functions, Kriging and Artificial Neural Networks. This research proposes a new metamodeling technique that uses Bezier curves and patches. The Bezier curve method is based on …

Review Of The Opnet It Guru Software, Jeng-Chung Victor Chen

Journal of International Technology and Information Management

The OPNET IT GURU has been in existence for years and designed to be used for the industry and the academics. The simulation software is now in version 10.0 and equipped with abundant features such as: modeling network topology and traffic, application impact assessment, and server capacity planning. The features of modeling network topology and traffic are ideal for network engineers to experiment different kinds of scenarios before implementation of any networks, which in turn could cost the organizations less on the IT budget. The application impact assessment is useful when measuring the end-to-end time of the deployed or to-be-deployed …

An Experimental Investigation Of The Differences In Subjective Pilot Workload Across Simulated And Real Flight Conditions, Todd V. Denning

Master's Theses - Daytona Beach

An investigation was undertaken to determine the difference in workload between simulated and real flight conditions. The results from the Modified Cooper-Harper and NASA-TLX did not show significance, however, the theoretical implications from the NASA-TLX subscales were of interest. As this is the first study comparing these two environments utilizing subjective workload measures, more research needs to take place in order to provide reliable and valid findings.

Simulation Activity Diagrams, John Ryan, Cathal Heavey

Conference papers

This paper presents a technique, Simulation Activity Diagrams (SAD), developed to lessen the modelling burden during the initial requirements gathering phases of a simulation project. The technique also allows the capture and visual communication of detailed information, to manufacturing personnel, which may otherwise be lost in detailed programming code.

Evaluation Of Scheduling Strategies On The Performance Of A Flexible Manufacturing Cell:A Simulation Study, Amr Arisha, Paul Young, Mohie El Baradie

Conference papers

The current trend in semiconductor manufacturing is characterized by expanding product variety, decreasing lead times from order to delivery, exacting standards of quality, and competitive prices. One possible means of achieving this is in the form of increased flexibility. Providing flexibility is typically an expensive proposition so, industrial engineers aim to provide more economic approaches to enable flexible manufacturing cells and related equipment to operate appropriately in an efficient manner. It is essential to characterize these tools in detail before the production plans are finalized. Using state-of-the-art computer simulation, a generic model of photolithography tools has been developed. The model …

Flow Shop Scheduling Problem: A Computational Study, Amr Arisha, Paul Young, Mohie El Baradie

Conference papers

A computational study has been developed to obtain optimal / near optimal solution for the flow shop scheduling problem with make-span minimization as the primary criterion and the minimization of either the mean completion time, total waiting time or total idle time as the secondary criterion. The objective is to determine a sequence of operations in which to process ‘n’ jobs on ‘m’ machines in same order (flow shop environment) where skipping is allowed. The Simulation approach for deterministic and stochastic flow shop scheduling has been developed. It reads and manipulates data for 500 jobs on 500 machines. Different factorial …

Physical-Statistical Modeling And Optimization Of Cardiovascular Systems, Dongping Du

USF Tampa Graduate Theses and Dissertations

Heart disease remains the No.1 leading cause of death in U.S. and in the world. To improve cardiac care services, there is an urgent need of developing early diagnosis of heart diseases and optimal intervention strategies. As such, it calls upon a better understanding of the pathology of heart diseases.

Computer simulation and modeling have been widely applied to overcome many practical and ethical limitations in in-vivo, ex-vivo, and whole-animal experiments. Computer experiments provide physiologists and cardiologists an indispensable tool to characterize, model and analyze cardiac function both in healthy and in diseased heart. Most importantly, simulation modeling empowers the …

Combining Activity-Based Costing With The Simulation Of A Cellular Manufacturing System, Paul Savory, Robert Williams, Rodney Rassmuseun

Department of Industrial and Management Systems Engineering: Faculty Publications

This paper presents an integrated simulation and activity-based management approach for determining the best sequencing scheme for processing a part family through a manufacturing cell. The integration is illustrated on a loop or U-shaped manufacturing cell and a part family consisting of four part types (A, B, C, and D). Production requirements for the cell demand that part batches be processed one type at a time. For example, all part A’s are processed until weekly demand is met, then part B’s, etc. The objective of this example is to determine the best part sequence (e.g., ABCD, DCBA or CABD). In …

Combining Activity-Based Costing With The Simulation Of A Cellular Manufacturing System, Paul Savory, Robert Williams, Rodney Rassmuseun

Department of Industrial and Management Systems Engineering: Faculty Publications

Discrete-event simulation is one of the most effective techniques for analyzing a manufacturing system. Unfortunately, little attention is given to using simulation models to estimate the economic impact of a proposed system configuration. This paper defines how activity-based costing (ABC) concepts can be incorporated into a discrete-event simulation model. Special emphasis is on demonstrating how decision making can be aided by having the simulation create a detailed “Bill of Activity” describing costs associated with manufacturing a part. The integration of ABC and simulation is illustrated by evaluating the impact of a proposed manufacturing cell configuration. The additional costing information aids …

A Web-Based Interface For Storing And Executing Simulation Models, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

The dominance of the Internet in the development of information and communication technology has made Web-based distributed solutions increasingly attractive. Apart from providing other services, the World Wide Web is being looked upon as an environment for hosting modeling and simulation applications. SIMAN is a simulation language that allows users to simulate discrete and continuous systems. In this research, a web-based interface or toolkit has been developed for storing and executing SIMAN simulation models over the Internet. This toolkit consists of a World Wide Web interface to SIMAN and a web-accessible database for storing user models. It provides users an …

A Web-Based Interface For Storing And Executing Simulation Model, Ashu Guru, Paul Savory, Robert Williams

Department of Industrial and Management Systems Engineering: Faculty Publications

The dominance of the Internet in the development ofinformation and communication technology has madeWeb-based distributed solutions increasingly attractive.Apart from providing other services, the World Wide Webis being looked upon as an environment for hostingmodeling and simulation applications. SIMAN is asimulation language that allows users to simulate discreteand continuous systems. In this research, a web-basedinterface or toolkit has been developed for storing andexecuting SIMAN simulation models over the Internet.This toolkit consists of a World Wide Web interface toSIMAN and a web-accessible database for storing usermodels. It provides users an easy-to-use environment fordeveloping text-based simulation models using the SIMANsimulation language. It also …

Simulation Modeling Presentations: The Life Cycle, Edward Yellig, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

A typical large scale simulation modeling project spans many months and encompasses activities such as problem definition, data collection, model development, experimentation, and scenario analysis. During the life cycle of a simulation project, numerous presentations are made to many different types of audiences. The purpose of these presentations will vary from seeking project approval, requesting information, discussing simulation model features, verifying the model, validating the model, presenting the experimental results, and offering model conclusions. This paper will discuss presentation techniques we used during a year-long simulation-modeling project. We will highlight techniques used for defining the purpose of each presentation, identifying …

Road Rescue Implements A Continuous Process Improvement Framework, John Olson, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

Continuous improvement programs traditionally focus on making small incremental improvements to a system. Unfortunately, their success can be limited due to the rapid changing environment within which most small companies operate. Improvement efforts should be flexible enough to capitalize on incremental and radical changes to a system. This paper presents a case analysis of how Road Rescue, an ambulance manufacturer, uses a continuous improvement framework to capitalize on both radical and incremental improvement opportunities. Results include a 10% increase in throughput, reduced cycle time of 44%, increased customer satisfaction, and higher quality.

Using Simulation To Derive Activity-Based Costing Estimates, Paul Savory, Robert Williams

Department of Industrial and Management Systems Engineering: Faculty Publications

This presentation showcases integrating activity based costing into the development of a SIMAN simulation of a manufacturing system.

Using Bayesian Statistics In Operational Testing, Thuan H. Tran

Theses and Dissertations

This research explored the applicability of Bayesian methods to the problem of determining the reliability of a series system, a parallel system, and a bridge system. The time to failure of each component in each system is assumed to be exponentially distributed. A basic exponential case and a basic binomial case are also evaluated. In general, using simulated data and real data when possible, the Bayesian methods produced confidence intervals that were much tighter than the classical inference methods, thus allowing a decision maker to have higher confidence in making a decision. System level data and aggregated component level data …

Simulation Model Of Fighter Pilot Assignment Process, Anthony J. Hutfles

Theses and Dissertations

This thesis analyzes the effect Continental United States (CONUS) Time on Station (TOS) has on filling critical rated assignments. A SIMSCRIPT II.5 simulation model of the F15 and F16 pilots assignment process was developed. The simulation tested the effect of changing CONUS TOS from 3 years to 6 years in half year increments. Analysis of the number of unfilled rated assignments from simulation runs of 10 years in length indicated that changing CONUS TOS by itself has no statistically significant effect on model's output. The analysis was expanded to a 2(2) factorial experimental design using CONUS TOS and Total Active …

An Integrated Approach To Simulation And Activity-Based Costing For Evaluating Alternative Manufacturing Cell Designs, Robert Williams, Paul Savory, Rodney Rasmussen

Department of Industrial and Management Systems Engineering: Faculty Publications

One effective technique for improving manufacturing efficiency involves the application of group technology part families and manufacturing cells. Selection of the best or optimum configuration of the manufacturing cell relies on the experience and judgment of the cell designer. This paper describes how activity-based costing (ABC) concepts can be integrated into a discrete-event simulation model and be used to evaluate manufacturing cell configurations. The output of the combined ABC simulation model provides a detailed “Bill of Activity” which allows the cell designer to consider costs as a critical factor in the cell design problem. Alternative cell configurations studied in this …

Simulating Queue Scheduling Policies For A Spacecraft Simulator, Paul Savory, Gene Saghi

Department of Industrial and Management Systems Engineering: Faculty Publications

The mission of the Cassini spacecraft is a unique opportunity to gain insights into major scientific questions about Saturn, the creation of the solar system, and the conditions that led to life on Earth. In preparation for the launch, NASA's Jet Propulsion Laboratory developed a software simulator to emulate the hardware data-control system of the spacecraft. Its primary use is to validate and verify commands that will be transmitted to the spacecraft. To improve the performance of the simulator, we used the SIMAN simulation language to model numerous queue-scheduling policies. Implementation of the simulation results combined with a software-code redesign …

Cycle Time Estimation For Simulating A Tandem Queueing Systems Using Aggregation Techniques, Paul Savory, Gerald Mackulak

Department of Industrial and Management Systems Engineering: Faculty Publications

One approach to simulating a single-server tandem queuing system is to explicitly model each of the production stages. In this paper, we apply queueing theory, a recursive algorithm, and composite random number sampling to develop an equivalent aggregate representation consisting of only a single production stage. Preliminary test results indicate that the aggregation works well for estimating the mean and variability of the total cycle time.

Using Mathematica To Aid Simulation Analysis, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

As computer power has increased, so has the capability of software developers to write programs that assist people with time-consuming tasks. Mathematica is such a program. The objective of this paper is to demonstrate how Mathematica, a symbolic programming environment, can be used to aid simulation analysis. In addition to a general discussion of Mathematica’s uses, advantages, and disadvantages, several examples will be presented. The examples include using Mathematica for distribution fitting, queueing analysis, random number generation, and creating a surface plot for optimization.

Issues In Developing An Undergraduate Simulation Course, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

Experience in developing an undergraduate simulation course is described. The course introduces the philosophies, principles, and methodologies for discrete-event simulation modeling. Strategy in choosing the course simulation software is discussed, plus important areas of teaching emphasis are highlighted.

The Integration Of Simulation And Reality For Education Enhancement And Training, Clarence Rasquinha, Stephen A. Raper

Engineering Management and Systems Engineering Faculty Research & Creative Works

Quite often, when engineers are exposed to a manufacturing environment on the job for the first time, they undergo a baptism by fire. The environment forces them to deal with situations that integrate many different bodies of knowledge. Reliance on concepts acquired in the academic environment is crucial to their success. Unfortunately, lacking in most academic environments, is any experience through which some or all of these concepts are integrated. In a continuing effort to enhance educational practices in Manufucturing/Systems Engineering programs and perhaps improve the preparedness of a young engineer, the CITE (Computer Integrated Technological Enterprise) tool offers educators …

A Robust Aggregation Approach To Simplification Of Manufacturing Flow Line Models, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

One of the more difficult tasks facing a modeler in developing a simulation model of a discrete part manufacturing system is deciding at what level of abstraction to represent the resources of the system. For example, questions about plant capacity can be modeled with a simple model, whereas questions regarding the efficiency of different part scheduling rules can only be answered with a more detailed model. In developing a simulation model, most of the actual features of the system under study must be ignored and an abstraction must be developed. If done correctly, this idealization provides a useful approximation of …

Scheduling A Medium-Sized Manufacturing Shop: A Simulation Study, Daniel J. Mcfeely

Theses and Dissertations

This study examined the application of simple-to-use, low cost scheduling methods to the operating environment of a medium-sized manufacturing shop. Computer simulation was used to evaluate eighteen different scheduling algorithms, each the result of the combination of a loading and a sequencing rule; due date setting was not considered since due dates are exogenously set. The loading rules investigated were Minimum Machine Required, Lowest Average WIP, and Lowest Average Aggregate Priority Level. The sequencing rules investigated were Priority, EDD, FIS, SPT, Slack, and Slack Ratio. The scheduling algorithms were evaluated against performance measures of mean tardiness, mean flowtime, mean percentage …

The Integration Of Tanker Aircraft Into Aslar, John S. Stieven

Theses and Dissertations

The purpose of this study was to analyze the proposed addition of heavy KC-135 tanker aircraft to the United States Air Force Aircraft Surge Launch and Recovery (ASLAR) instrument approach system. The Air Force Communications Command, which oversees ASLAR operations, will use these results to determine if KC-135 aircraft should be permitted to fly ASLAR approaches. A SIMSCRIPT II.5 animated simulation model was developed to simulate the Runway 26 approach at Seymour Johnson Air Force Base under a variety of wind conditions. This model was expanded to show the feasibility of KC-135s flying ASLAR approaches and to determine proper controller …

Integrating Psychological Operations Into The Joint Theater Level Simulation (Jtls), C. Matthew Pecot Iii

Theses and Dissertations

This thesis provides a prototype and methodology for integrating psychological operations (PSYOP) into the Joint Theater Level Simulation (JTLS) combat model. The requirement rose out of the need for aggregate-level training models to reflect the role of PSYOP so that commanders and their staffs can learn how to manage plan for, and conduct PSYOP within the context of AirLand battle doctrine. As the JTLS model currently exists, there is no representation of psychological operations whatsoever. This thesis outlines a methodology for incorporating the PSYOP analysis process (including the target audience analysis), the PSYOP product development and production process, the PSYOP …

Enhancements To The Animated Tutor For Air Combat Simulation, David A. Legge

Theses and Dissertations

This study investigates the use of the Ada programming language in combat modeling. It takes an existing combat model, the Animated Tutor for Air Combat Simulation (ATACS), and re-writes it into Ada. The new model also includes enhancements to the original model. ATACS+, as it is now called, is used as a learning tool in combat modeling classes at the Air Force Institute of Technology. ATACS+ consists of a preprocessor and a model, complete with two and three-dimensional graphics and engagement status reports. Conclusion are made about Ada's suitability for combat modeling, some of the features of Ada which can …