Engineering Commons^™

Optimization Of Human Interactions In The College Campus Model Via Simio Integration, Benjamin E. Chaback

Doctoral Dissertations and Master's Theses

College campuses are a significant part of life in some cities. Many students each year attend university, pursuing additional knowledge from faculty members. Both staff and faculty members rely on these students to have successful jobs and to ensure the university functions. Yet recently, more and more students are attending, leading to overcrowding, lower admission rates, and difficulty getting into good programs. Previous work exists on qualitative student affairs and quantitative retention data, yet little on using simulations to model this problem. This work aimed to (a) Determine the ability to successfully model human interactions/people flow on a college campus, …

Resources Based Planning Framework For Infrastructure Maintenance And Rehabilitation Projects, Heba Gad

Theses and Dissertations

Infrastructure maintenance and rehabilitation projects involve activities scattered over a large geographical area (e.g., scattered road segments maintenance, telecom towers maintenance program, etc.). Planning such projects require a resource-based approach that accounts for the implications of resource mobility between activities’ locations in terms of time & cost. Existing scheduling techniques fall short of addressing the unique challenges of the scattered nature of these projects in combination with organization's limited resources availability. To address this need, this research presents a resources-based planning framework for infrastructure maintenance and rehabilitation scattered projects with the objective of enhancing resources utilization achieving time and cost …

Essays On Perioperative Services Problems In Healthcare, Amogh S. Bhosekar

All Dissertations

One of the critical challenges in healthcare operations management is to efficiently utilize the expensive resources needed while maintaining the quality of care provided. Simulation and optimization methods can be effectively used to provide better healthcare services. This can be achieved by developing models to minimize patient waiting times, minimize healthcare supply chain and logistics costs, and maximize access. In this proposal, we study some of the important problems in healthcare operations management. More specifically, we focus on perioperative services and study scheduling of operating rooms (ORs) and management of necessary resources such as staff, equipment, and surgical instruments. We …

Evaluating The Military Medical Evacuation Dispatching And Delivery Problem Via Simulation And Self-Exciting Hawkes Process, Virbon B. Frial

Theses and Dissertations

The location, allocation, and utilization of military medical evacuation (MEDEVAC) resources significantly impact the quality and timeliness of medical care to injured troops. In 2009, Secretary of Defense Robert Gates introduced the Golden Hour mandate that entails the evacuation of critically-injured troops to military treatment facilities (MTFs) within an hour to prevent further complications. To develop high-quality policies that improve MEDEVAC system performance, several papers in the current literature assume that MTFs have both the capacity and capability of treating any patient, regardless of the type of injury. However, these assumptions are unrealistic when conducting high-intensity operations. While acknowledging MTF …

Integrating Cost As A Decision Variable In Wargames, Joshua N. Reese, Jonathan D. Ritschel, Brent T. Langhals, Ryan D. Engle

Faculty Publications

The US military can no longer afford to be reactive, leaving critical cost analyses to the months and years following operations or full-scale conflicts. By leveraging cost in wargaming as part of the Joint planning process, DOD can provide Congress and the American taxpayers a range of potential costs associated with various military engagements that reflect fiscal and operational realities.

Bmap/G/C Queueing Model With Group Clearance Useful In Telecommunications Systems – A Simulation Approach, Srinivas Chakravarthy, Alexander Rumyantsev

Industrial & Manufacturing Engineering Publications

Queueing models in which customers or messages arrive in batches with inter-arrival times of batches possibly correlated and services rendered in batches of varying sizes play an important role in telecommunication systems. Recently queueing models of BMAP/G/1-type in which a new type of group clearance was studied using embedded Markov renewal process as well as continuous time Markov chain whose generator has a very special structure. In this paper, we generalize these models to multi-server systems through simulation approach. After validating the simulation model for the single server case, we report our simulated results for much more general situations.

Foster Care Support Foundation Volunteer And Capital Outreach Analysis, Abeer Bhatti, Alexandro Martinez, Sunny Patel, Desmond Vail

Senior Design Project For Engineers

Care Support Foundation (FCSF) provides free goods to children in Georgia. Annually, 11,000 volunteers are needed to deal with the massive influx of donations and fundraising events. Through our analyses, we aim to make recommendations to the FCSF, which can help raise funds and implement mitigating strategies that would increase funds and improve the foundation.

Theory And Practice Of Supply Chain Synchronization, Michael Prokle

Doctoral Dissertations

In this dissertation, we develop strategies to synchronize component procurement in assemble-to-order (ATO) production and overhaul operations. We focus on the high-tech and mass customization industries which are not only considered to be very important to create or keep U.S. manufacturing jobs, but also suffer most from component inventory burden. In the second chapter, we address the deterministic joint replenishment inventory problem with batch size constraints (JRPB). We characterize system regeneration points, derive a closed-form expression of the average product inventory, and formulate the problem of finding the optimal joint reorder interval to minimize inventory and ordering costs per unit …

Guidelines For Scheduling In Primary Care: An Empirically Driven Mathematical Programming Approach, Hyun Jung Alvarez Oh

Doctoral Dissertations

Primary care practices play a vital role in healthcare delivery since they are the first point of contact for most patients, and provide health prevention, counseling, education, diagnosis and treatment. Practices, however, face a complex appointment scheduling problem because of the variety of patient conditions, the mix of appointment types, the uncertain service times with providers and non-provider staff (nurses/medical assistants), and no-show rates which all compound into a highly variable and unpredictable flow of patients. The end result is an imbalance between provider idle time and patient waiting time. To understand the realities of the scheduling problem we analyze …

A Study Of Queuing Theory In Low To High Rework Environments With Process Availability, Adam J. Brown

Theses and Dissertations--Manufacturing Systems Engineering

In manufacturing systems subject to machine and operator resource constraints the effects of rework can be profound. High levels of rework burden the resources unnecessarily and as the utilization of these resources increases the expected queuing time of work in process increases exponentially. Queuing models can help managers to understand and control the effects of rework, but often this tool is overlooked in part because of concerns over accuracy in complex environments and/or the need for limiting assumptions. One aim of this work is to increase understanding of system variables on the accuracy of simple queuing models. A queuing model …

Customer Management Analysis Of Irish Plumbing & Heating Distribution System: A Simulation Study, Amr Arisha, Amr Mahfouz, John Crowe, Finbarr Bennett

Conference papers

The sudden burst of the property bubble, coupled with current global economic conditions has resulted in a huge decrease in demand for plumbing and heating fixtures in the Irish construction industry. Moreover, inefficient supply chain management policies have imposed further pressures on companies resulting in more system bottlenecks and unnecessary costs. Inventory management is seen as a functional area that can ease such bottlenecks and in turn increase supply chain efficiency, decrease costs and increase customer satisfaction. The challenge is to predict the balance of on-hand inventory and order quantity to optimise customer satisfaction and minimise inventory cost. It is …

Police Operations Simulation, Robert Mcgee

Industrial and Manufacturing Engineering

In this report, the author explains the process of creating the Police Operations Simulation, shows step-by-step how it works, and statistically analyzes the results from SLOPD’s own proposed and current schedules. The data-gathering from the department and the simulation itself will receive the bulk of the coverage in this report, followed by sample results from SLOPD and a business plan for future sale to other departments.

Using the given numbers, it appears that the proposed schedule will result in significantly improved coverage for the city of San Luis Obispo. While any increase in the number officers on patrol tends to …

Practical Simulation Application: Evaluation Of Process Control Parameters In Twisted-Pair Cables Manufacturing System, Amr Mahfouz, Said Hassan, Amr Arisha

Articles

Intensive competition and rapid technology development of Twisted-Pair Cables (TPC) industry have left no room for competing manufacturers to harbour system inefficiencies. TPC are used in various communication and networks hardware applications; their manufacturing facilities face many challenges including various product configurations with different equipment settings, different product flows and Work in Process (WIP) space limitations. The quest for internal efficiency and external effectiveness forces companies to align their internal settings and resources with external requirements/orders, or in different words, significant factors must be set appropriately and identified prior to manufacturing processes. Integrated definition models (IDEF0, IDEF3) in conjunction with …

Simulation Model To Investigate Flexible Workload Management For Healthcare And Servicescape Environment, Michael Thorwarth, Paul Harper, Amr Arisha

Conference papers

High demand and poor staffing conditions cause avoidable pressure and stress among healthcare personnel which results in burnout symptoms and unplanned absenteeism which are hidden cost drivers. The work environment within an emergency department is commonly arranged in a flexible workload which is highly dynamic and complex for the outside observer. Using detailed simulation modeling within structured modeling methods, a comprehensive model to characterize the nurses' time utilization in such flexible dynamic workload environment was investigated. The results have been used to derive a generalized analytic expression that describes certain settings that lead to an instable queuing system with serious …

Course Portfolio - Discrete Event Simulation, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

This course portfolio, written by Dr. Paul Savory, provides an overview of his Discrete Event Simulation course at the University of Nebraska-Lincoln. It offers an overview of the course goals, a summary of the classroom activities for achieving them, and a detailed assessment of student learning. He highlights his introduction of the simul8 programming environment to his students. In addition to exploring his students’ learning, Dr. Savory also explores different approaches for documenting his teaching by including multimedia clips (video and audio), uses graphs, uses color, and incorporates images. The resulting portfolio is one that can be reviewed, shared, and …

Details And Description Of Operations Research, Paul Savory

Industrial and Management Systems Engineering: Reports

The ambiguous term operations research was coined during World War II. A frequent substitute is management science. Operations research is a scientific approach to analyzing problems and making decisions. It uses mathematics and mathematical modeling on computers to forecast the implications of various choices and zero in on the best alternatives. This content paper provides an overview of operations research. It highlights operations research problems, methods for solving problems, different areas of operations research, and example problems.

Process Modelling Support For The Conceptual Modelling Phase Of A Simulation Project, Cathal Heavey, John Ryan

Conference papers

While many developments have taken place around supporting the model coding task of simulation, there are few tools available to assist in the conceptual modelling phase. Several authors have reported the advantages of using process modelling tools in the early phases of a simulation project.

This paper provides an overview of process modelling tools in relation to their support for simulation, categorizing the tools into formal method and descriptive methods. A conclusion from this review is that none of the tools available adequately support the requirements gathering phase of simulation. This is not surprising as none of the process modelling …

Requirements Gathering For Simulation, John Ryan, Cathal Heavey

Conference papers

This paper discusses the current shortfalls in support for the pre-coding phases of a discrete event simulation project. The paper then presents a process modelling technique, Simulation Activity Diagrams (SADs), developed to specifically support the initial requirements gathering phases of a simulation project. The paper concludes with an outline of proposed future developments to the modelling technique.

Process Modeling For Simulation, John Ryan, Cathal Heavey

Articles

This paper discusses shortfalls in relation to the requirements gathering phases of simulation. While many developments have taken place around supporting the model coding task of simulation, there are few tools available to assist in the requirements gathering phase. This is surprising as it has been reported by several researchers that the requirements phase can absorb twice as much resources as the coding phase. There are numerous process modeling tools available (over 100) that can and have been used to support the requirements phase of simulation. This paper provides a selective review of some of the most important in relation …

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 …

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 …

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 …

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.

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 …

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 …