Operations Research, Systems Engineering and Industrial Engineering Commons^™

Optimal Maintenance For Stochastically Degrading Satellite Constellations, Timothy J. Cook

Theses and Dissertations

This thesis develops a methodology to determine an optimal policy for maintaining a satellite constellation that degrades over time. Previous work has developed a methodology to compute an optimal replacement policy for a satellite constellation in which satellites were viewed as binary entities, either operational or failed. This research extends the previous models by developing an optimal maintenance policy for satellite constellations in which each satellite may operate in a finite number of degraded states. The constellation is assumed to consist of a finite number of satellites, each with a finite number of functions with distinct failure mechanisms. Assuming each …

Strategic Airlift En Route Analysis And Considerations To Support The Global War On Terrorism, Michael C. Sere

Theses and Dissertations

The Global War on Terrorism has mandated the need for additional global en route airfields. En route airfields consist of bases that are strategically located at intermediate locations between the Continental United States and the intended theater of operations. These airfields serve as refueling, crew staging, or maintenance stops for strategic airlift aircraft flying transoceanic routes. The focus of this study is to examine concepts to meet this need and to address important aspects that should be considered in devising new en route strategies. Based on various important factors associated with potential en route airfields, a goal programming methodology was …

Barriers To Electronic Records Management (Erm): An Exploratory Case Study Investigating Erm In The Deployed Environment During Operations Enduring Freedom And Iraqi Freedom, Brian G. Hobbs

Theses and Dissertations

Corporate and government organizations can use electronic records as an important strategic resource, if the records are managed properly. In addition to meeting legal requirements, electronic records can play a vital role in the management and operation of an organization's activities. Corporate America is facing challenges in managing electronic records, and so too is the U.S. Air Force (USAF). The deployed environment is particularly problematic for electronic records management (ERM). This research, thus, investigates ERM in the deployed environment to identify and characterize the barriers faced by USAF personnel who deployed to locations supporting Operations Enduring Freedom and Iraqi Freedom. …

The Feasibility Of The U.S. Air Force Mandating The Exclusive Use And Purchase Of Forest Stewardship Council Certified Wood And Paper Containing 100% Post Consumer Content, Silinda Johnson

Theses and Dissertations

The Resource Conservation and Recovery Act required federal agencies to purchase products with the highest recovered content (or post-consumer content in the case of paper) as practicable. The Office of Federal Procurement Policy required all executive agencies to give preference in their procurement programs to products that conserve natural resources and protect the environment. These requirements necessitate that the Air Force consider purchasing 100% post-consumer content (PCC) paper and Forest Stewardship Council (FSC) certified wood because of their environmentally preferable attributes. This study compared the availability, performance standards, and prices of 100% PCC paper to 30% PCC paper and FSC-certified …

Development Of A Process Modelling System For Simulation, John Ryan

Other resources

This thesis details the development of a process modelling technique to aid a simulation model developer during the requirements gathering and conceptual modelling phases of a simulation project.

There are a number of process modelling techniques available that are capable of being used during such phases of a simulation project, however there is currently a lack of process modelling techniques developed specifically to aid a simulation model developer in capturing, representing and communicating information and systems issues to persons involved in the operation of discrete systems under investigation.

A detailed review of the literature related to techniques capable of supporting …

Using Multi-Stack And Variable-Speed-Drive Systems To Reduce Laboratory Exhaust Fan Energy, Gang Wang, Mingsheng Liu

Durham School of Architectural Engineering and Construction: Faculty Publications

In buildings that contain laboratories, fume hoods are normally used to control contaminant concentrations. Exhaust stacks with a constant exit velocity are required to make sure that dangerous concentrations do not occur in occupied areas near the building or on the roof top. To achieve constant velocity when exhaust flow rates are less than design, makeup air is introduced to the system at the inlet of the exhaust fan. Since laboratory exhaust airflow is often significantly less than the design airflow, exhaust fans consume significantly more energy than is necessary. To reduce exhaust fan energy, techniques involving multiple exhaust stacks …

Evaluating The Impact Of Production Scheduling On Tool Performance, 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. Simulation provides an effective decision support tool in scheduling of semiconductor manufacturing. Simulation model was developed as a risk assessment tool for one of the implant process area. The model examines the impact of production schedule on tool performance by testing different production scenarios. Production ramping, local buffer capacity, product sequence and product mix seem to be influential factors of the …

Simulation In Semiconductor Manufacturing Facilities, Amr Arisha, Paul Young

Conference papers

Semiconductor manufacturing is one of the most complex industries in terms of technology and manufacturing procedure. The life cycle of a semiconductor facility (FAB) has many phases, in their life cycle including capacity planning, new products introduction, variation of products/technologies, and decline phase. The complexity of the manufacturing and the external forces from markets and technology growth make predicting the effects of changes in the manufacturing system problematic. Simulation, if used correctly, is a powerful hands-on tool which may be used to give a better insight of the effect of engineering/management decisions on the performance of the manufacturing system. While …

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 …

Decision Factors For Cooperative Multiple Warhead Uav Target Classification And Attack With Control Applications, Douglas D. Decker

Theses and Dissertations

Autonomous wide area search, classification and attack using Unmanned Combat Air Vehicles (UCAVs) is considered. The wide area search and attack scenario is modeled, capturing important problem parameters related to environment, seeker, and munitions. Probabilistic analysis is used to formulate and analytically solve for various probabilities, including the probability of mission success. Two methods are utilized. The first examines the sub-events required for various events to occur. The second utilizes a Markov chain approach. General expressions are first obtained that are applicable to any assumed a priori distributions of targets and false targets. These expressions are subsequently applied to a …

A Case Study Of Teaching A Quantitative Course Using Archived Streaming Video, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

This case study highlights some of the issues and difficulties experienced in teaching a quantitative course using three methods of delivery: in-class to an audience of students, television broadcast over a satellite system to distance students, and archived streaming video accessible by students. The discussion is applicable to administrators and faculty exploring the option of teaching a course using multiple delivery approaches.

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 …

Review Of The Product Development Process And Information Flow In The Manufacturing Industry: Problems And A Possible Wav Forward, E Opiyo

Tanzania Journal of Engineering and Technology (TJET)

No abstract provided.

Keys To Successful Implementation And Sustainment Of Managed Maintenance For Healthcare Facilities, Elizabeth A. Waggoner

Theses and Dissertations

Health care providers are faced with two critical issues in today's evolving marketplace: lowering operational costs and achieving more efficient, cost-effective methods to deliver high quality patient care. The rising costs of healthcare and decreasing budgets have placed additional strain on the United States Air Force Medical Service to aggressively lower its facilities' costs. With fewer funds and less personnel, the Air Force medical service is re-evaluating its current maintenance outsourcing implementation practices and reexamining how these strategies might be implemented and sustained more successfully. This research offers some of the foundational needs for designing, implementing and sustaining any type …

Investigating The Optimal Management Strategy For A Healthcare Facility Maintenance Program, Daria J. Gaillard

Theses and Dissertations

Reacting to the need to transform and the increasing pressure to outsource all non-core activities, Air Force Material Command Surgeon General discontinued its previous use of full service contracts with original equipment manufacturers and adopted a relatively new maintenance outsourcing strategy: strategic partnering with an equipment management firm. The objective of this study is to create a decision-model for selecting the optimal management strategy for a healthcare organization's facility maintenance program. This study used personal interviews with facility management personnel from MAJCOMs to collect and analyze data. This study offers a re-conceptualized framework for viewing and understanding the various maintenance …

Phase-Type Approximations For Wear Processes In A Semi-Markov Environment, Christopher J. Solo

Theses and Dissertations

The reliability of a single-unit system experiencing degradation (wear) due to the influence of a general, observable environment process is considered. In particular, the failure time distribution is evaluated using only observations of the unit's current operating environment which is characterized as a finite semi-Markov process (SMP). In order to impose the Markov property, generally distributed environment state sojourn times are approximated as phase-type (PH) random variables using observations of state holding times and transition rates. The use of PH distributions facilitates the use of existing analytical results for reliability evaluation of units subject to an environment process that evolves …

Thin-Film Simulation Model For Comparing Production Schedules In A Semiconductor Fabrication Facility, Amr Arisha, Paul Young

Conference papers

Analysis of advanced manufacturing systems in any manufacturing industry requires certain level of knowledge about the system. Flexible manufacturing cells, in particular, are commonly used in most wafer fabrication to provide the ability to change product without requiring the construction of new manufacturing plant. This level of flexibility comes at a significant capital cost and, in order to achieve the maximum potential of each cell, it is essential to characterize and establish the performance of these cells in detail before a new production plan is implemented. Using state-of-the-art computer simulation and a structured modelling methodology a generic model of flexible …

Applications Of Simulation In Semiconductor Manufacturing Facilities, Amr Arisha, Paul Young

Conference papers

Semiconductor fabrication facilities face many challenges through the many phases of their life cycle including design, build, various production ramps, and many levels of production. Confronted with global competition and rapidly changing technology and customer requirements, there is an increasing demand for rapid solution techniques to improve efficiency in manufacturing. The complexities and forces of both market and the process combine to make the use of simulation crucial at many different planning and control levels. While not a panacea for sustainable performance, simulation provides an effective vehicle for defining the path from competitive concepts to real world solutions and gives …

Adapting An Effective Interface For A Passive Solar System With A Truncated Pyramid Concentrator, Shirley M. Flinders

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science and Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Masters of Science by Shirley M. Flinders on December 3, 2003.

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.

A Simulation Model To Characterize Photolithography Process Of A Semiconductor Wafer Fabrication, Amr Arisha, Paul Young, Mohie El Baradie

Conference papers

The pressures on semiconductor manufacturers due to cost considerations, rapid growth of process technology, quality constraints, feature size reduction, and increasingly complex devices are increasing requiring ever higher efficiency from the manufacturing facilities. The complexity of manufacturing high capacity semiconductor devices means that it is impossible to analyze the process control parameters and the production configurations using traditional analytical models. There is, therefore, an increasing need for effective models of each manufacturing process, characterising and analyzing the process in detail, allowing the effect of changes in the production environment on the process to be predicted. The photolithography process is one …

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 …

On The Selection Of Simulation Software For Manufacturing Application, Amr Arisha, Mohie El Baradie

Conference papers

The growing complexity of manufacturing along with the need for higher efficiency, greater flexibility, better product quality and lower cost urged the use of simulation in manufacturing systems. The number and variety of simulation software packages on the market increased as well. Consequently, the varieties of these packages led to some bewilderment on the part of potential users when faced the selection process. The present article addresses an overview of material addressed in journals, conferences, and textbooks on the selection of appropriate simulation software. It also suggests a classification of main criteria to be considered in evaluating simulation software packages. …

Compare And Complexity - When Is Compare Not Enough?, Chris E. Greiman

Theses and Dissertations

The purpose of this case study research is to determine the utility of COMPARE, the DoD approved software for conducting A-76 competitions, in the more complex world of public-private competition. COMPARE serves as the baseline for establishing cost factors, while two Air Force Depots are used as a basis of comparison. Research questions answered are: 1. What are the baseline cost comparison factors established in COMPARE? 2. What are the common cost factors found in the Air Force Depot public-private competitions? 3. What are the similarities and differences between the cost factors established in COMPARE and those used in the …

How Can The Air Force Maximize The Value Of Reverse Auctioning As A Pricing Technique?, Cynthia L. Marion-Mullins

Theses and Dissertations

This research examines the pricing tool reverse auctioning. In a reverse auction buyers state the item they wish to buy and the sellers compete with each other for the sale, driving the price steadily down until no seller is willing to go any lower. Darleen A. Druyun, Principal Deputy Assistant Secretary of the Air Force for Acquisition and Management, Washington, D.C., launched the Air Force acquisition reform "Lightning Bolts" initiatives. These initiatives jump-start acquisition reform to find processes leading towards a better, faster, and cheaper way of conducting business. A reverse auction is one of these processes. A review of …

Decision Analysis With Value Focused Thinking As A Methodology To Select Force Protection Initiatives For Evaluation, David M. Jurk

Theses and Dissertations

Current emphasis on homeland security/defense is high. Decision makers responsible for enhancing the protection of both military and civilian personnel require additional insight when selecting ideas, concepts, or technologies to pursue with constrained resources. They are faced with multiple criteria and multiple objectives; yet they have no defensible, objective, and repeatable selection process to assist them in making their decisions. This thesis explores whether the value-focused thinking (VFT) process is appropriate for providing the necessary insight to those decision makers. To prove the VFT process is appropriate and viable; this thesis focuses on constructing a value model, scoring alternatives, and …

Task Load And Automation Use In An Uncertain Environment, Mark A. Daly

Theses and Dissertations

The purpose of this research was to investigate the effects that user task load level has on the relationship between an individual's trust in and subsequent use of a system's automation. Automation research has demonstrated a positive correlation between an individual's trust in and subsequent use of the automation. Military decision-makers trust and use information system automation to make many tactical judgments and decisions. In situations of information uncertainty (information warfare environments), decision-makers must remain aware of information reliability issues and temperate their use of system automation if necessary. An individual's task load may have an effect on his use …

A System Dynamics Approach To Modeling Aircraft System Production Break Costs, John J. Dubelko

Theses and Dissertations

This research effort employs a System Dynamics methodology to model Air Force aircraft production break costs. The Air Force currently used the Anderlohr, Modified Anderlohr, and Retrograde methods for the estimation of aircraft production breaks. These methods offer little insight into the dynamic behavior of an aircraft production break. System Dynamics offers a unique way of capturing expert opinions in this area and dynamically presenting behaviors of an Air Force aircraft production line during a production break. Development of this model followed a four-step process of conceptualization, formulation, testing, and implementation. Five Air Force aircraft production break experts in were …

An Empirical Investigation Of Critical Factors Affecting The Ability Of Public Entities To Compete In Public Private Competitions, Timothy J. Gilbride

Theses and Dissertations

In 1996, the Commandant of the U.S. Coast Guard initiated the largest ever service acquisition program to re-capitalize Coast Guard assets. Called the Integrated Deepwater System or IDS, this acquisition effort seeks to renovate, modernize, and or replace the Coast Guard s entire portfolio of ships, aircraft, and support facilities. The IDS contractor will be responsible for designing and constructing the system, as well as, sharing responsibility for supporting and disposing of it. This poses a significant threat to the USCG Aircraft Repair and Supply Center (AR&SC), the Coast Guard s aircraft depot located in Elizabeth City, North Carolina. The …